Photon-number superselection and the entangled coherent-state representation University of Calgary | Publication | 2003-10-01 | B. C. Sanders, S. D. Bartlett, T. Rudolph, P. L. Knight |

Nonclassical fields and the nonlinear interferometer University of Calgary | Publication | 1999-12-01 | B. C. Sanders, D. A. Rice |

Geometric Phase of Three-Level Systems in Interferometry University of Calgary | Publication | 2001-01-01 | B. C. Sanders, H. d. Guise, S. D. Bartlett, W. Zhang |

Finite detection window in photon coincidence spectroscopy University of Calgary | Publication | 1998-01-01 | B. C. Sanders, L. Horvath, B. F. Wielinga |

Optimal quantum measurements for phase-shift estimation in optical interferometry University of Calgary | Publication | 1997-07-01 | B. C. Sanders, G. J. Milburn, Z. Zhang |

Optimal Quantum Measurements for Phase Estimation University of Calgary | Publication | 1995-10-01 | B. C. Sanders, G. J. Milburn |

Superpositions of distinct phase states by a nonlinear evolution University of Calgary | Publication | 1992-06-01 | B. C. Sanders |

Quantum-noise reduction in intracavity four-wave mixing University of Calgary | Publication | 1990-12-01 | B. C. Sanders, M. D. Reid |

Quantum nondemolition measurement of quantum beats and the enforcement of complementarity University of Calgary | Publication | 1989-12-01 | B. C. Sanders, G. J. Milburn |

Phase variables and squeezed states University of Calgary | Publication | 1986-06-01 | B. C. Sanders, S. M. Barnett, P. L. Knight |

Single photons on demand University of Calgary | Publication | 2005-03-01 | B. C. Sanders, J. Vuckovic, P. Grangier |

Introduction University of Calgary | Publication | 2007-01-01 | B. C. Sanders, Y. Yamamoto, A. Zeilinger |

Science without borders University of Calgary | Publication | 2008-05-01 | B. C. Sanders |

Large optical nonlinearities with few photons University of Calgary | Publication | 2011-02-01 | B. C. Sanders |

Review of entangled coherent states University of Calgary | Publication | 2012-01-01 | B. C. Sanders |

Connection between the N00N state as a superposition of SU(2) coherent states University of Calgary | Publication | 2014-01-01 | B. C. Sanders, C. C. Gerry |

Monogamy and polygamy of entanglement in multipartite quantum systems University of Calgary | Publication | 2010-01-01 | B. C. Sanders, J. Kim |

Visualizing the silicon quantum computer University of Calgary | Publication | 2008-01-01 | B. C. Sanders, L. Hollenberg, D. Edmundson, A. Edmundson |

Quantum quincunx in cavity quantum electrodynamics University of Calgary | Publication | 2003-01-01 | B. C. Sanders, S. D. Bartlett, B. Tregenna, P. L. Knight |

Entangled coherent states University of Calgary | Publication | 1992-05-01 | B. C. Sanders |

On the road to optical quantum information science University of Calgary | Publication | 2007-01-01 | B. C. Sanders |

Classical vs Quantum Fingerprinting University of Calgary | Publication | 2005-05-01 | B. C. Sanders |

Sharing quantum secrets: Theory and Experiment University of Calgary | Publication | 2004-01-01 | B. C. Sanders |

Si-C Bond Formation on Silicon Surfaces Using Tetraalkylammonium Salts as the Source of Alkyl Groups University of Calgary | Publication | 2005-01-01 | B. C. Sanders |

Elements of quantum information science University of Calgary | Presentation | 2005-04-06 | B. C. Sanders |

Atomic qubit in decoherence-suppressed subspace University of Calgary | Presentation | 2004-05-05 | B. C. Sanders, G. P. Brooke |

Photonic crystal antennas University of Calgary | Presentation | 2003-12-01 | B. C. Sanders |

Quantum cryptography: an overview University of Calgary | Presentation | 2006-05-24 | B. C. Sanders |

Security in quantum networks University of Calgary | Presentation | 2004-09-30 | B. C. Sanders |

Quantum Fuel for Quantum Informatics University of Calgary | Presentation | 2004-03-24 | B. C. Sanders |

Rolling quantum dice University of Calgary | Presentation | 2006-11-15 | B. C. Sanders |

Quantum computing and quantum complexity University of Calgary | Presentation | 2007-03-13 | B. C. Sanders |

Efficiently simulating evolution of states on a quantum computerFeynman [Int. J. Theoret. Phys. 21, 467-488 (1982)] suggested that a quantum computer could serve as an efficient simulator of state evolution in cases where classical algorithms are inefficient, and Lloyd [Science 273, 1073-1078 (1996)] provided the first rigorous analysis of this conjecture. Using primitives introduced by Aharonov and Ta-Shma [Proc. 35th Annual ACM Symp. on Theory of Computing, 20-29 (2003)] for studying adiabatic quantum state generation, we introduce a quantum algorithm for simulating state evolution by a time-independent Hamiltonian whose cost is nearly linear in time (and we prove that an algorithm whose cost is sub-linear in time cannot exist) and nearly quadratic in terms of the sparseness of the Hamiltonian for sparse Hamiltonian evolution [Berry, Ahokas, Cleve and Sanders, Comm. Math. Phys. 270: 359-371 (2007)]. I will also discuss our efforts to establish an efficient simulation of state evolution for time-dependent Hamiltonians that is comparable to our time-independent Hamiltonian result.
University of Calgary | Presentation | 2007-05-24 | B. C. Sanders |

Efficient quantum algorithm for simulating state evolution University of Calgary | Presentation | 2007-06-28 | B. C. Sanders |

Quantum walking via superconducting circuit quantum electrodynamicsThe quantum walk is the quantum analogue to the ubiquitous random walk in Physics and has recently yielded efficient quantum algorithms for decision trees. We show how a quantum walk, with a single walker and controllable decoherence, can be implemented for the first time by using a quantum quincunx created in superconducting circuit quantum electrodynamics (QED). Two resonators are employed to provide simultaneously fast readout and controllable decoherence over a wide range of parameters, and the Hadamard coin flip is achieved by directly driving the cavity. University of Calgary | Presentation | 2008-09-28 | B. C. Sanders |

Entanglement swapping with imperfect sources and detectors University of Calgary | Presentation | 2008-08-23 | B. C. Sanders |

Quantum computing: animations and simulationsThe quantum computer is the ultimate in quantum technology: revolutionizing computer science by transforming otherwise intractable problems into efficiently solvable problems but requiring exquisite levels of quantum control with only the minutest tolerance of decoherence. I will use animated movies to explain how a quantum computer would function and explain our efforts to realize quantum computing on the surface of silicon. Then I will discuss our work on efficient algorithms for simulating Hamiltonian evolution on a quantum computer in the spirit of the first proposed application of a quantum computer by Richard Feynman. University of Calgary | Presentation | 2009-02-18 | B. C. Sanders |

Towards an experimental realization of a quantum walk with a coin: Superconducting circuit quantum electrodynamics & trapped ion The quantum walk is one of the most important protocols for quantum computing as well as being a beautiful quantization of the ubiquitous random walk of stochastic processes. The random walk is demonstrated by a quincunx (Galton Board), and a quantum quincunx would demonstrate quantum walks in an analogous way. However, experimentally realizing a quantum walk with one walker whose motion is governed by a single two-sided coin is elusive. The challenge arises because of the need to flip coherently the coin and then to entangle the coin and walker's motion, all in an environment with controllable decoherence to interpolate between the quantum walk and the random walk. I will discuss how a quantum walk on a circle in phase space could be realized via supeconducting circuit quantum electrodynamics, with the Cooper pair box serving as a charge qubit, and how a quantum walk on a line could be realized by a single trapped ion with a two-level electronic structure. University of Calgary | Presentation | 2009-02-17 | B. C. Sanders |

Electron superhighway through a protein complex University of Calgary | Presentation | 2009-04-01 | B. C. Sanders |

On continuous variable quantum algorithms for oracle identification problemsWe establish a framework for oracle identification problems in the continuous variable setting, where the stated problem necessarily is the same as in the discrete variable case. Continuous variables are manifested through a continuous representation in an infinite-dimensional Hilbert space. We apply this formalism to the Deutsch-Jozsa problem and show that, due to an uncertainty relation between the continuous representation and its Fourier-transform dual representation, the corresponding Deutsch-Jozsa algorithm is probabilistic hence forbids an exponential speed-up. University of Calgary | Presentation | 2009-06-10 | B. C. Sanders |

Electron superhighways and bridges in protein complexesDoes Natural Selection optimize biomachinery at the quantum level? Does quantum coherence play a role in biochemical electron transport? We show
that a particular redox protein complex is configured so that metastable water bridges act as "superhighways" for coherent electron transport between its constituent protein molecules. The bridge enables fast coherent electron transport across the gap instead of dooming the electron to slow thermal hopping through the interprotein medium. Although our study focuses on a particular protein complex
that has been frozen and characterized by crystallography, we conjecture that bridge-building is ubiquitous for redox processes.
University of Calgary | Presentation | 2009-06-19 | B. C. Sanders, N. Babcock, A. l. De, D. Salahub |

An introduction to "Continuous variable" quantum information is an important niche area of quantum information science. The success of this area is driven by impressive experimental advances with preparation, processing and measurement of squeezed light. Certain quantum information tasks were first demonstrated in the "continuous variable" setting such as deterministic quantum teleportation and quantum threshold secret sharing. "Continuous variable" quantum cryptography is an exciting prospect for high-bandwidth local-area information-theoretic security. On the other hand, the concept of
continuous variables is anathema to the discrete mathematical structure of standard computer science and information theory, and these problems are especially evident in the challenge of constructing error correction strategies. I will present the basics of "continuous variable" quantum information and discuss how coding can be implemented in the "continuous variable" setting. We will also see how the Deutsch-Jozsa quantum algorithm translates to the "continuous
variable" domain and see in particular how the time-bandwidth product rule for Fourier transforms creates a severe limitation.
University of Calgary | Presentation | 2009-06-23 | B. C. Sanders |

How to build a quantum computer and what to do with itQuantum computing is an exciting area of research because of the prospect of solving problems that are believed to be intractable on any classical (i.e. non-quantum) computer. Unfortunately a quantum computer is hard to build. Also, when we do make a quantum computer, it will be small so what interesting things can we do with it? I will use animated films to show how quantum computers are being built and explain the problems with these schemes. Then I will explain how a small-scale quantum computer could be used to simulate the properties of quantum systems. University of Calgary | Presentation | 2009-11-18 | B. C. Sanders |

Monogamy and polygamy of entanglement for qudit University of Calgary | Presentation | 2009-11-13 | B. C. Sanders |

Few-photon all-optical switching University of Calgary | Presentation | 2010-07-13 | B. C. Sanders, A. Kamli, K. Marzlin, S. Moiseev, Z. Wang |

Quantum computing: how It could transform our worldThe race is on to build quantum computers. Described as “nuclear bombs for the internet,” quantum computers would make obsolete all the security and encryption methods now in place that make e-commerce — and modern digital life — possible. But quantum computers also promise to solve complex problems thought to be impossible without quantum technology, for example providing accurate weather predictions and designs for new quantum materials with astounding properties. Barry Sanders, Director of the Institute for Quantum Information Science at the U. of C. brings us up-to-date on the race to build quantum computers, worldwide and here in Alberta. University of Calgary | Presentation | 2010-11-12 | B. C. Sanders |

Autler-Townes Splitting vs Electromagnetically Induced Transparency in ExperimentsAbstract: Autler-Townes splitting and electromagnetically induced transparency both yield a transparency window controlled by the pump field, but only electromagnetically induced transparency yields strong transparency for a weak pump field. Some experiments report observation of electromagnetically induced transparency when Autler-Townes splitting has instead been demonstrated. We introduce an objective method, based on Akaike's information criterion, to discern objectively whether electromagnetically induced transparency or Autler-Townes splitting has been seen. University of Calgary | Presentation | 2011-05-31 | B. C. Sanders |

Electrons cross a dynamically-organized inter-protein water bridge for directed efficient transfer University of Calgary | Presentation | 2011-09-02 | B. C. Sanders |

Quantum information and computation for quantum chemistry University of Calgary | Presentation | 2013-03-17 | B. C. Sanders |

Quantum interferometry for computation: estimating immanants from photon coincidences University of Calgary | Presentation | 2013-07-29 | B. C. Sanders |

BosonSampling with non-simultaneous photonsQuantum computing aims to transform certain classically hard
computational problems into easy-to-solve problems by using the
resources of quantum computation, but onerous space and time resources
are required to answer problem instances beyond the reach of current
classical computational capability. The BosonSampling problem
introduces a new paradigm to quantum computing by seeking efficient
sampling of a distribution of matix transformations, weighted by the
submatrix permanents. Scaling current photon interferometer technology
to dozens of photons in more than double the number of interferometric
channels puts this form of quantum computing within reach of violating
the extended Church thesis of computer science for the first time.
This thesis will be falsified empirically if a quantum computer, even
a problem-specific purpose-built system such as photonic
interferometery that eschews quantum bits and quantum gates, solves a
computational problem efficiently in a case where classical computing
is believed not to solve the same problem efficiently. We review the
BosonSampling problem and recent dramatic experimental successes to
realize the system for few photons. Then we discuss the importance and
unavoidability of non-simultaneity of photon arrivals and how we
propose using photon-arrival statistics parametrized by delay times to
characterize inteferometers and sample with respect to submatrix
immanants rather than submatrix permanents. Our work shows that
non-simultaneity is a strength rather than a weakness in
interferometric BosonSampling.
University of Calgary | Presentation | 2013-09-09 | B. C. Sanders |

Evolutionary algorithms for hard quantum control University of Calgary | Presentation | 2014-03-25 | B. C. Sanders |

Arrow of time, and other temporal conundrums University of Calgary | Presentation | 2005-06-26 | B. C. Sanders |

Deterministic entanglement of assistance in quantum networks University of Calgary | Presentation | 2005-06-02 | B. C. Sanders |

Quantum information processing with continuous variablesQuantum information theory is built on creating, manipulating and reading qubits yet some of the dramatic experimental successes, such as unconditional quantum teleportation, quantum cryptography with coherent states, and threshold quantum secret sharing, have been achieved for continuous variables. I will explain continuous variable quantum information processing, discuss its realizations as quantum optics experiments, expose the weaknesses, extol the strengths, and consider its future.
The field of continuous variable quantum information processing is exciting on several levels. The mathematics is elegant, and the quantum optics experiments can be understood in terms of Hamiltonians that obey the symplectic algebra. The experiments make use of sophisticated, yet well-developed, technology such as the ability to squeeze the vacuum fluctuations of light, perform balanced homodyne detection, and prepare highly coherent states of light. Decoherence is often negligible in these settings. These advantages make continuous variable quantum information processing the best avenue for first proofs-of-concept.
The field faces formidable challenges, including encoding quantum information into continous variables allowing for robust error correction, achieving nonlinear transformations outside the symplectic transformations that allow universal unitary transformations of the field without significant decoherence, and security proofs for quantum cryptography. These challenges are not insurmountable; rather they add to the excitement of the field, which I will discuss.
University of Calgary | Presentation | 2004-06-14 | B. C. Sanders |

Symemetry and measurement in quantum interferometry University of Calgary | Presentation | 1998-09-21 | B. C. Sanders |

Sharing Quantum Secrets University of Calgary | Presentation | 2003-10-17 | B. C. Sanders |

Improving single photon sources via postprocessing with linear optics and photodetection University of Calgary | Presentation | 2003-11-28 | B. C. Sanders |

Large cross-phase modulation between slow co-propagating weak pulse in rubidium University of Calgary | Presentation | 2006-08-13 | B. C. Sanders, Z. Wang, K. Marzlin |

Decoherence, errors, and correction in quantum information processingI will explain decoherence and error correction for one and more qubits
in terms of the master equation, the circuit model, and the completely positive
map, culminating with an explanation of one of the most important results
in quantum information: the threshold theorem for fault-tolerant quantum
computation.
University of Calgary | Presentation | 2006-08-04 | B. C. Sanders |

Quantum building blocks: making quantumworks work University of Calgary | Presentation | 2006-09-27 | B. C. Sanders |

Applied QKD University of Calgary | Presentation | 2006-10-04 | B. C. Sanders |

Secret sharing and concealing a bit in GHZ states University of Calgary | Presentation | 2006-11-27 | B. C. Sanders |

Harmonic oscillatorology for quantum informationalists University of Calgary | Presentation | 2007-01-04 | B. C. Sanders |

Multi-partite entangled Gaussian states and su (1,1) symmetry University of Calgary | Presentation | 2007-05-23 | B. C. Sanders, Z. Shaterzadeh-Yazdi, P. Turner |

Challenges of optical quantum information science University of Calgary | Presentation | 2007-04-10 | B. C. Sanders |

Information-theoretic security for authenticated long-distance quantum key distribution with partial trust networksQuantum key distribution must overcome two important hurdles: authentication to avoid the man-in-the-middle attack and relays or repeaters to allow long-distance communication. Current feasible approaches suggest complete trust of intermediate nodes in a network. We show that, in a network of partially trusted nodes (even with a low level of trust), our scheme enables probabilistic information-theoretic secure authentication and long-distance key distribution based on existing quantum key distribution technology, thus making our approach feasible now without reliance on total trust of intermediate nodes.
University of Calgary | Presentation | 2007-06-02 | B. C. Sanders |

Duality for monogamy of entanglement University of Calgary | Presentation | 2007-06-24 | B. C. Sanders |

Efficient quantum algorithm for simulating evolution of states University of Calgary | Presentation | 2007-06-21 | B. C. Sanders |

Quantum information at the University of Calgary University of Calgary | Presentation | 2007-08-25 | B. C. Sanders |

Polygamy of entanglement of assistance: duality monogamy inequality for entanglement University of Calgary | Presentation | 2007-09-10 | B. C. Sanders |

Quantum algorithm for efficient simulating Hamiltonian evolution University of Calgary | Presentation | 2007-09-05 | B. C. Sanders |

Efficient algorithm for universal simulationWe show how Hamiltonian evolution can be simulated in a black-box setting with a cost that is nearly linear in time and nearly constant in size of the system given a sparse Hamiltonian.
Collaboration with G. Ahokas, D. Berry, R. Cleve, P. Hoyer, and N. Wiebe.
University of Calgary | Presentation | 2007-12-01 | B. C. Sanders |

Quantum walk on a circle in phase space via superconducting circuit quantum electrodynamicsWe show how a quantum walk, with a single walker and controllable decoherence, can be implemented
for the first time in a quantum quincunx created via superconducting circuit quantum electrodynamics (QED). Two resonators are employed to provide simultaneously fast readout and controllable decoherence over a wide range of parameters. The Hadamard coin flip is achieved by directly driving the cavity, with the result that the walker jumps between
circles in phase space but still exhibits quantum walk behavior over 15 steps. University of Calgary | Presentation | 2008-03-12 | B. C. Sanders, P. Xue, A. Blais, K. Lalumière |

Incoherently generated coherence and immunity to decoherenceThe decoherence free subspace is important as states in this subspace are immune to the decohering effects of open system dynamics. We introduce a new kind of state, which, for certain open system dynamics, can be made immune to decoherence by driving the system with an appropriate driving field: we refer to these states as incoherently generated coherent states, and they are pure states that evolve unitarily despite coupling to the open system. The seemingly non-unitary open system driving term becomes essential as a partner with the driving field to generate coherences that stabilize these special states. We prove that such states cannot exist for most open system models with finite-dimensional systems but are readily found for infinite-dimensional systems, and we present examples of such states for suitable open systems. University of Calgary | Presentation | 2008-05-29 | B. C. Sanders, R. Karasik, K. Marzlin, B. K. Whaley |

Simulating Hamiltonian evolution on a quantum computerEfficiently simulating arbitrary Hamiltonian evolution was the earliest motivating application for quantum computation, yet its algorithmic formulation is less advanced than those addressing search and factorization problems. Here we present an efficient quantum algorithm for simulating quantum state evolution for a sparse time- independent Hamiltonian in terms of computing its matrix elements. For n qubits and at most a constant number of nonzero entries in each row, and a constant bound on the norm of the Hamiltonian, our algorithm cost is nearly linear in time and nearly constant in space [1]. We show how the algorithm can be adapted for efficiently simulating time- dependent Hamiltonian evolution of a state on a quantum computer with similar costs [2].\r\n University of Calgary | Presentation | 2008-07-29 | B. C. Sanders |

Escaping decoherenceDecoherence is the bane of quantum information, and putting states into decoherence-free subspaces is one strategy to avoid this destruction of quantum information. The bad news is that we have found that decoherence-free subspaces do not exist for extended systems in more than one dimension for a broad class of realistic reservoirs, but the good news is that we have discovered that in some cases the environment protects certain states by disallowing them from decohering via a nudging process from the unitary part of the open system dynamics. Examples given from cavity quantum electrodynamics and squeezed light. University of Calgary | Presentation | 2008-06-10 | B. C. Sanders, R. Karasik, K. Marzlin, B. K. Whaley |

Quantum Information Science in Calgary University of Calgary | Presentation | 2008-08-23 | B. C. Sanders |

Oracle identification problem and a Deutsch-Jozsa type of algorithm for 'continuous variable' quantum information University of Calgary | Presentation | 2008-10-24 | B. C. Sanders |

Towards quantum information processing on a silicon surface University of Calgary | Presentation | 2008-11-15 | B. C. Sanders |

Efficient algorithm for quantum simulationThe original motivation for quantum computation was the efficient simulation of quantum systems to overcome the exponential barrier of classical algorithms. When small-scale quantum computers are created, quantum simulations are likely to be the first applications.
Here we formulate an algorithm for simulation of any Hamiltonian-driven dynamics of a finite quantum system, which fully accounts for all resources used in the computation. We show that our generic algorithm has a cost that is nearly linear in time, cannot be sublinear in time, and is nearly constant in space (number of qubits) for given sparseness of the Hamiltonian matrix. Our algorithm exploits higher-order corrections to the Trotter formula and an efficient graph theory method for decomposing the Hamiltonian matrix into a sum of one-sparse Hamiltonian matrices.
University of Calgary | Presentation | 2008-11-12 | B. C. Sanders |

Giant cross-phase modulation for two slowed co-propagating pulses University of Calgary | Presentation | 2008-07-01 | B. C. Sanders, Z. Wang, K. Marzlin, S. Moiseev |

Quantum cryptography for information-theoretic security University of Calgary | Presentation | 2010-06-14 | B. C. Sanders |

Dangling-bond charge qubit on a silicon surface University of Calgary, University of Alberta | Presentation | 2010-07-23 | B. C. Sanders, L. Livadaru, P. Xue, Z. Shaterzadeh-Yazdi, A. G. DiLabio, J. Mutus, L. J. Pitters, R. A. Wolkow |

Machine learning with swarm intelligence for adaptive quantum measurementsAdaptive feedback schemes are promising for quantum-enhanced measurements yet are complicated to design. Machine learning can autonomously generate algorithms in a classical setting. Here we adapt machine learning for quantum information and use our framework to generate autonomous adaptive feedback schemes for quantum measurement. In particular our approach replaces guesswork in quantum measurement by a logical, fully-automatic, programmable routine. We show that our method yields schemes that outperform the best known adaptive scheme for interferometric phase estimation. University of Calgary | Presentation | 2010-11-05 | B. C. Sanders |

Electromagnetically induced transparency in superconducting circuitsI discuss Autler-Townes splitting and electromagnetically induced transparency in superconducting\r\ncircuits, how to incorporate lasing without inversion, and the benefit of extending from\r\none to several atoms.\r\n University of Calgary | Presentation | 2011-06-07 | B. C. Sanders |

Nonlinear quantum optics in superconducting circuit quantum electrodynamic systems University of Calgary | Presentation | 2011-05-09 | B. C. Sanders |

Doing science with IranIran has transformed from a magnificent empire to a global pariah in just 2500 years. The news is replete with stories of fatwas, stoning, kidnappings, repression, and the nuclear program. The United Nations Security Council has sanctions on Iran for enriching uranium, and the US Department of the Treasury has imposed restrictions on sponsoring conferences in Iran and on publishing scientific papers from Iran. Although sanctions are important for diplomacy and containment, so is outreach. I argue that engaging Iranian scientists through collaboration and conferences within Iran is morally right and strategically advantageous, and I share my own conference-organizing experiences in Iran to support this assertion. University of Calgary | Presentation | 2011-02-22 | B. C. Sanders |

Autler-Townes splitting vs. electromagnetically induced transparency: objective criterion to discern between them in any experimentAutler-Townes splitting (ATS) and electromagnetically-induced transparency (EIT) both yield a transparency window in an absorption profile, but only EIT yields strong transparency for a weak pump field, due to Fano interference, whereas ATS does not. Fano interference thus makes EIT especially valuable for sensing, so discriminating EIT from ATS is important but so far has been subjective. We introduce an objective method, based on Akaike's information criterion, to test ATS vs. EIT from experimental data and determine which pertains. We apply our method to a recently reported induced-transparency experiment in superconducting circuit quantum electrodynamics. University of Calgary | Presentation | 2011-03-24 | B. C. Sanders |

Empirically discerning Autler-Townes splitting from electromagnetically induced transparencyI discuss Autler-Townes splitting vs electromagnetically induced transparency in superconducting circuits, how to incorporate lasing without inversion by converting a Lambda to a Delta system, and how to extend from one to several atoms to create optical depth. University of Calgary | Presentation | 2011-05-26 | B. C. Sanders |

Quantum optics in superconducting circuits University of Calgary | Presentation | 2011-10-26 | B. C. Sanders |

Seeing through electromagnetically induced transparencyElectromagnetically controlling transparency is important for fast optical switching and sensitive metrology and is usually ascribed to coherent population trapping. On the hand Autler-Townes splitting also describes electromagnetically induced transparency for a strong pump. Fully classical versions of electromagnetically induced transparency are also reported. Variants arise such as vacuum induced transparency. Here i explain the physics of electromagnetically induced transparency and Autler-Townes splitting and how discern between them and show how effective classical coupled oscillators can be at describing the phenomenon. I also show how the novel effect of electromagnetically induced transparency with amplification could be realized in superconducting circuit quantum electrodynamics. University of Calgary | Presentation | 2011-07-01 | B. C. Sanders |

Security through quantum communicationQuantum communication is important for information-theoretic secure key distribution through public channels as well as for beating standard limits to information transfer in finite-bandwidth channels and for performing distributed quantum computation. Practical and theoretical quantum communication are advancing rapidly but key challenges remain. I present the current state of the field and some promising research activities now underway. University of Calgary | Presentation | 2012-05-10 | B. C. Sanders |

Forty-five years of entangled coherent statesI review entangled coherent state research since its first implicit use in 1967 to the present. Entangled coherent states are important to quantum superselection principles, quantum information processing, quantum optics, and mathematical physics. Despite their inherent fragility, entangled coherent states have been produced in a conditional propagating-wave quantum optics realization. Fundamentally the states are intriguing because they entangle the coherent states, which are in a sense the most classical of all states of a dynamical system. University of Calgary | Presentation | 2012-11-26 | B. C. Sanders |

Introduction to quantum information and computing University of Calgary | Presentation | 2013-01-03 | B. C. Sanders |

Efficient algorithm for designing universal quantum circuits to simulate efficiently open-system quantum dynamics University of Calgary | Presentation | 2013-02-25 | B. C. Sanders |

Artificial-intelligence reinforcement learning for quantum metrology with adaptive measurementsQuantum metrology aims for measurements of quantum channel (or process) parameters that are more precise than allowed by classical partition noise (shot noise) given a fixed number of input particles. Specifically the imprecision of the process-parameter estimate scales inversely with the square root of the number of particles in the classical domain and up to inverse-linear in the number of particles in the quantum domain by exploiting entanglement between particles. Quantum adaptive-measurement schemes employ entangled-particle inputs and sequential measurements of output particles with feedback control on the channel in order to maximize the knowledge gain from the subsequent particles being sequentially processed. Quantum-adaptive approaches have the advantage that input states are expected to be easier to make experimentally than for non-adaptive schemes.
We are interested in devising input states and adaptive feedback control on the processes to beat the standard quantum-measurement limit in real-world scenarios with noise, decoherence and particle losses. As such procedures are difficult to find even in ideal cases, the usual method of clever guessing is inadequate for this purpose. Instead we employ artificial-intelligence machine learning to find adaptive-measurement procedures that beat the standard quantum limit. I will discuss our approaches using reinforcement learning and evolutionary computation to finding procedures for adaptive interferometric phase estimation and show that machine learning has enabled us to find procedures in the ideal case that outperform previously known best cases in the ideal noiseless, decoherence-free, lossless scenario as well as easily devising robust procedures for noisy, decoherent, lossy scenario. University of Calgary | Presentation | 2013-02-21 | B. C. Sanders |

Quantum frameness for charge-parity-time inversion symmetryPhysical laws are invariant under simultaneous charge-parity-time (CPT) inversion, which is due to relativistic Lorentz covariance and the linearity of quantum mechanics. We show that CPT-superselection can be circumvented by employing a system that possesses CPT frameness, and we construct such resources in two cases: for massive spin-zero particles and for Dirac-spinors. In the case of spin-zero particles, we explicitly construct and quantify all resourceful pure states. Our approach is to treat CPT inversion unitarily by considering the aggregate action of the CPT transformation, rather than sequentially composing a unitary and two anti-unitary transformations, thereby overcoming a major drawback of circumventing time-inversion symmetry alone using an anti-unitary transformation University of Calgary | Presentation | 2013-03-21 | B. C. Sanders |

Multi-atom collective effects and electromagnetically induced transparency in one-dimensional waveguides University of Calgary | Presentation | 2013-05-21 | B. C. Sanders |

Collective atomic effects in waveguide quantum electrodynamicsRapid experimental advances with superconducting circuits have ushered in the new field of one-dimensional quantum optics with tunable artificial atoms. I discuss our theoretical and experimental work on subradiance, superradiance, electromagnetically induced transparency and cross-phase modulation with artificial atoms in waveguide quantum electrodynamics. [Collaborations with H. Alotaibi, A. Blais, A. Fedorov, K. Lalumière, P. M. Leung, A. F. van Loo, and A. Walraff] University of Calgary | Presentation | 2013-05-27 | B. C. Sanders |

Characterizing coherently-coupled dangling-bond dynamics University of Calgary | Presentation | 2013-10-18 | B. C. Sanders |

Quantum simulations of quantum channels University of Calgary | Presentation | 2013-11-11 | B. C. Sanders |

On measuring coherence in coupled dangling-bond dynamics University of Calgary | Presentation | 2013-12-03 | B. C. Sanders |

Efficient quantum simulation of a quantum channel University of Calgary | Presentation | 2013-11-16 | B. C. Sanders |

Re-shaping the technology landscape in Alberta, with help from global networks University of Calgary | Presentation | 2014-02-26 | B. C. Sanders |

Quantum electrodynamics in linelandQuantum electrodynamic phenomena, such as spontaneous emission from an atom or coupling between two dipoles, sensitively depend on the dimension of the surrounding space. The intrigue of dimensional dependence is whimsically related in Abbott’s story about a Square living in two-dimensional Flatland [1]. The Square tries to comprehend three-dimensional Spaceland from a visiting Sphere, and, in a separate tale, the Square tries to explain the second dimension to the Points inhabiting one-dimensional Lineland.
Superconducting circuits with inbuilt artificial atoms, based on using Josephson junctions to realize nonlinear oscillators with quantized energy levels, enable us to realize Quantum Electrodynamics in Lineland. Lineland turns out to be a technological wonderland, with easy access to strong dipole coupling, excellent mode matching and non-abating dipole-dipole coupling over long distances. In particular we explore coherent and collective effects of artificial atoms in Lineland and their technological implications [2-5].
[1] Edwin Abbott Abbott, Flatland: A Romance of Many Dimensions (1884).
[2] J. Joo, J. Bourassa, A. Blais and B. C. Sanders, Electromagnetically-induced transparency with amplification in superconducting circuits, Physical Review Letters 105(7): 073601 (2010).
[3] P. M. Leung and B. C. Sanders, Coherent control of microwave pulse storage in superconducting circuits , Physical Review Letters 109(25): 253603 (2012).
[4] K. Lalumière, B. C. Sanders, A. F. Van Loo, A. Fedorov, A. Wallraff and A. Blais, Input-output theory for waveguide QED with an ensemble of inhomogeneous atoms, Physical Review A 88(4): 043806 (2013).
[5] A. F. Van Loo, A. Fedorov, K. Lalumière, B. C. Sanders, A. Blais and A. Wallraff, Photon-mediated interactions between distant artificial atoms, Science 342(6165), 1494-1496 (2013).
University of Calgary | Presentation | 2014-04-04 | B. C. Sanders |

Giant nonlinearity with double-EIT in rubidium University of Calgary | Presentation | 2005-10-16 | B. C. Sanders, Z. Wang, K. Marzlin |

Security aspects of practical quantum cryptography University of Calgary | Presentation | 2000-12-10 | B. C. Sanders, G. Brassard, N. Lutkenhaus, T. Mor |

Topological phase in three-level atom University of Calgary | Presentation | 1999-07-07 | B. C. Sanders, P. W. Zhang |

Vector phase in quantum interferometry University of Calgary | Presentation | 1998-12-14 | B. C. Sanders, A. Mann |

Putting the Q into cavity QED University of Calgary | Presentation | 1998-09-27 | B. C. Sanders |

A description of the quantised nonlinear March-Zehnder interferometer University of Calgary | Presentation | 1997-12-10 | B. C. Sanders, A. D. Rice |

Theoretical quantum optics University of Calgary | Presentation | 2004-06-22 | B. C. Sanders |

QViz (dinner speech) University of Calgary | Presentation | 2005-10-18 | B. C. Sanders |

Highly nonclassical photon statistics in parametric down conversionWe use photon counters to obtain the joint photon counting statistics from twin-beam non-degenerate parametric down conversion, and we demonstrate directly, and with no auxiliary assumptions, that these twin beams are nonclassical.
University of Calgary | Presentation | 2006-06-12 | B. C. Sanders, E. Waks, E. Diamanti, Y. Yamamoto |

The su(1,1) symmetry of tripartite entangled Gaussian statesTwo-mode squeezed light has been central to theoretical and experimental studies of continuous variable quantum information processing and to quantum foundations. More recently the generalization of these states to three-mode squeezed light has been achieved in the context of quantum teleportation [1] and state sharing [2]. Theories are typically developed in Gaussian or position representations, but we have discovered that all tripartite entangled Gaussians states of these types are in fact su(1,1) coherent states with respect to an intriguing three-boson realization of su(1,1) first noticed by Sebawe Abdalla et al [3]. This symmetry provides insights into the useful properties of these states and suggests ways to generalize theories and applications of multipartite entangled Gaussian states. [1] A. Furusawa et al, Science \textbf{282}, 706 (1998). [2] A. M. Lance et al, Phys. Rev. Lett. \textbf{92}, 177903 (2004). [3] M. Sebawe Abdalla et al, Eur. Phys. J. D \textbf{13}, 423 (2001).
University of Calgary | Presentation | 2007-03-08 | B. C. Sanders, Z. Shaterzadeh-Yazdi, P. Turner |

Time-ordered decompositions of exponential operators generated by time-dependent hamiltoniansFor a given error tolerance, we find an effcient decomposition of a matrix exponential, generated by a time-dependent Hamiltonian, into a time-ordered sequence of matrix exponentials generated by pre-determined Hamiltonians. University of Calgary | Presentation | 2008-06-05 | B. C. Sanders |

Low-loss nonlinear polaritonicsLow-loss nonlinear polaritonics1 BARRY SANDERS, Uni-\r\nversity of Calgary, SERGEY MOISEEV, Kazan Physical-Technical\r\n We propose large low-loss cross-phase modulation be-\r\ntween two coupled surface polaritons propagating through a double\r\nelectromagnetically-induced transparency medium situated close to a\r\nnegative-index metamaterial. A mutual pi phase shift is attainable be-\r\ntween the two pulses at the single photon level. University of Calgary | Presentation | 2010-05-29 | B. C. Sanders, S. Moiseev, A. Kamli |

Simulating time-dependent quantum dynamics on a quantum computer University of Calgary | Presentation | 2011-03-04 | B. C. Sanders |

Quantum simulations II University of Calgary | Presentation | 2013-01-05 | B. C. Sanders |

Quantum frameness for CPT symmetryWe develop a theory of charge-parity-time (CPT) frameness resources to circumvent CPT superselection. We construct and quantify such resources for spin-0, 1/2, 1, and Majorana particles and show that quantum information processing is possible even with CPT superselection. Our method employs a unitary representation of CPT inversion by considering the aggregate action of CPT rather than the composition of separate C, P, and T operations, as some of these operations involve problematic antiunitary representations. University of Calgary | Presentation | 2013-09-27 | B. C. Sanders |

Evolutionary algorithms for adaptive quantum metrologyQuantum metrology (e.g., precise displacement measurements using interferometers or precise temporal measurements using atomic clocks) aims to beat the standard quantum limit imposed by a combination of the uncertainty principle and a lack of entanglement resources. Furthermore quantum metrology aims for the ultimate quantum limit of minimal uncertainty in the variable being measured.
Adaptive quantum metrology is a modified procedure that uses feedback and control to reach for the same limit while avoiding the overhead of having to perform (effectively entangling) joint measurements on the output (photons in interferometry and atoms in clocks). Adaptive procedures are hard to devise even in ideal cases such as noiseless isolated metrological systems.
I show how we employ machine learning in the form of evolutionary algorithms to devise adaptive procedures that are superior to those devised by human minds. Our procedure for devising adaptive feedback procedures is effective even for noisy cases. This work is important not only for quantum metrology but also as a first step to new, powerful methods for quantum control.
University of Calgary | Presentation | 2014-01-30 | B. C. Sanders |

Forty-five years of entangled coherent states University of Calgary | Publication | 2013-11-01 | B. C. Sanders |

Efficient algorithms for universal quantum simulation University of Calgary | Publication | 2013-07-01 | B. C. Sanders |

Quantum optics in superconducting circuits University of Calgary | Publication | 2011-10-01 | B. C. Sanders |

Quantum cryptography for information-theoretic security University of Calgary | Publication | 2012-01-01 | B. C. Sanders |

Building a relationship with China University of Calgary | Publication | 2016-01-01 | B. C. Sanders |

Enhanced nonlinear susceptibility via double-double electromagnetically induced transparency University of Calgary | Publication | 2016-01-01 | B. C. Sanders, H. M. Alotaibi |

Requirement for quantum computation University of Calgary | Publication | 2003-01-01 | S. D. Bartlett, B. C. Sanders |

Relation between classical communication capacity and entanglement capability for two-qubit unitary operations University of Calgary | Publication | 2003-09-01 | D. W. Berry, B. C. Sanders |

Entanglement capability of a self-inverse Hamiltonian evolution University of Calgary | Publication | 2003-07-01 | X. Wang, B. C. Sanders |

Asymmetric double barrier resonant tunnelling structures with improved characteristics University of Calgary | Publication | 1999-04-01 | J. -. Shi, B. C. Sanders, S. -. Pan |

Inconsistency in the Application of the Adiabatic Theorem University of Calgary | Publication | 2004-10-01 | K. Marzlin, B. C. Sanders |

Quantum size effects in metal-induced Si(111) surface reconstructions University of Calgary | Publication | 2000-10-01 | K. -. Jin, B. C. Sanders, S. -. Pan, G. -. Yang |

Entangled coherent states for systems with SU (2) and SU (1,1) symmetries University of Calgary | Publication | 2000-10-01 | X. Wang, B. C. Sanders, S. Pan |

Cavity-enhanced parametric down-conversion as a source of correlated photons University of Calgary | Publication | 2000-08-01 | P. Hariharan, B. C. Sanders |

Efficient Classical Simulation of Optical Quantum Information Circuits University of Calgary | Publication | 2002-10-01 | S. D. Bartlett, B. C. Sanders |

How to share a continuous-variable quantum secret by optical interferometry University of Calgary | Publication | 2002-04-01 | T. Tyc, B. C. Sanders |

Photon coincidence spectroscopy for two-atom cavity quantum electrodynamics University of Calgary | Publication | 2002-01-01 | L. Horvath, B. C. Sanders |

Multipartite entangled coherent states University of Calgary | Publication | 2001-12-01 | X. Wang, B. C. Sanders |

Numerical analysis of capacities for two-qubit unitary operations University of Calgary | Publication | 2005-02-01 | D. W. Berry, B. C. Sanders |

Operational formulation of homodyne detection University of Calgary | Publication | 2004-07-01 | T. Tyc, B. C. Sanders |

Canonical entanglement for two indistinguishable particles University of Calgary | Publication | 2005-01-01 | X. Wang, B. C. Sanders |

Remote Preparation and Distribution of Bipartite Entangled States University of California, San Diego, University of Calgary | Publication | 2004-12-01 | G. Gour, B. C. Sanders |

Perturbative corrections to photon coincidence spectroscopy University of Calgary | Publication | 2001-08-01 | L. Horvath, B. C. Sanders |

Near-optimal two-mode spin squeezing via feedback University of Calgary | Publication | 2002-07-01 | D. W. Berry, B. C. Sanders |

Row structure in metal-induced Si(111) surface reconstructions University of Calgary | Publication | 2001-01-01 | K. Jin, B. C. Sanders, S. Pan, G. Yang |

Requirement of Optical Coherence for Continuous-Variable Quantum Teleportation University of Calgary | Publication | 2001-07-01 | T. Rudolph, B. C. Sanders |

Improving performance of resonant tunneling devices in asymmetric structures University of Calgary | Publication | 2001-06-01 | J. Shi, B. C. Sanders, S. Pan, E. M. Goldys |

Superpositions of SU (3) coherent states via a nonlinear evolution University of Calgary | Publication | 2001-03-01 | K. Nemoto, B. C. Sanders |

Multiatom effects in cavity QED with atomic beams University of Calgary | Publication | 1999-09-01 | H. J. Carmichael, B. C. Sanders |

Multiphoton coincidence spectroscopy University of Calgary | Publication | 1999-08-01 | L. Horvath, B. C. Sanders, B. F. Wielinga |

Representations of the Weyl group and Wigner functions for SU(3) University of Calgary | Publication | 1999-01-01 | D. J. Rowe, B. C. Sanders, H. d. Guise |

Determination of quantized electromagnetic-field state via electron interferometry University of Calgary | Publication | 1998-09-01 | A. Vourdas, B. C. Sanders |

Complementarity and entangled coherent states University of Calgary | Publication | 1998-06-01 | D. A. Rice, B. C. Sanders |

Self-trapping and self-focusing of a coherent atomic beam University of Calgary | Publication | 1997-08-01 | W. Zhang, B. C. Sanders, W. Tan |

Stability of Atomic Bose-Einstein Condensate with Negative Scattering Length University of Calgary | Publication | 1996-11-01 | W. Zhang, B. C. Sanders, A. Mann |

Squeezing and antisqueezing in homodyne measurements University of Calgary | Publication | 1996-05-01 | M. S. Kim, B. C. Sanders |

Bell’s inequality for an entanglement of nonorthogonal states University of Calgary | Publication | 1995-02-01 | A. Mann, B. C. Sanders, W. J. Munro |

Resonance fluorescence of a two-level atom in an off-resonance squeezed vacuum University of Calgary | Publication | 1994-02-01 | Z. Ficek, B. C. Sanders |

Atomic beamsplitter: reflection and transmission by a laser beam University of Calgary | Publication | 1994-02-01 | W. Zhang, B. C. Sanders |

Theory of photon correlations in a double-detector scheme University of Calgary | Publication | 1991-11-01 | C. W. Gardiner, B. C. Sanders |

Quantum beats in two-atom resonance fluorescence University of Calgary | Publication | 1990-01-01 | Z. Ficek, B. C. Sanders |

Focus on Single Photons on Demand University of Calgary | Publication | 2004-01-01 | P. Grangier, B. C. Sanders, J. Vuckovic |

Quantum teleportation of composite systems via mixed entangled states University of Calgary | Publication | 2006-09-01 | S. Bandyopadhyay, B. C. Sanders |

Quantum walks on circles in phase space via superconducting circuit quantum electrodynamics University of Calgary | Publication | 2008-01-01 | P. Xue, B. C. Sanders, A. Blais, K. Lalumière |

Double-double electromagnetically induced transparency with amplification University of Calgary | Publication | 2014-01-01 | H. M. Alotaibi, B. C. Sanders |

Graph states for quantum secret sharing University of Calgary | Publication | 2008-01-01 | D. Markham, B. C. Sanders |

Nearest-neighbor coupling asymmetry in the generation of cluster states in a charge-qubit structure University of Calgary | Publication | 2010-01-01 | P. Xue, B. C. Sanders |

Ordered measurements of permutationally-symmetric qubit strings University of Calgary | Publication | 2011-02-01 | A. Hentschel, B. C. Sanders |

Unified entropy, entanglement measures and monogamy of multi-party entanglement University of Calgary | Publication | 2011-01-01 | J. Kim, B. C. Sanders |

Two quantum walkers sharing coins University of Calgary | Publication | 2012-01-01 | P. Xue, B. C. Sanders |

Coherent control of microwave pulse storage in superconducting circuits University of Calgary | Publication | 2012-01-01 | P. M. Leung, B. C. Sanders |

Controlling and reversing the transition from classical diffusive to quantum ballistic transport in a quantum walk by driving the coin University of Calgary | Publication | 2013-01-01 | P. Xue, B. C. Sanders |

Accessing quantum secrets via local operations and classical communication University of Calgary | Publication | 2013-01-01 | V. Gheorghiu, B. C. Sanders |

Fermionized photons in the ground state of one-dimensional coupled cavities University of Calgary | Publication | 2013-01-01 | A. D'Souza, B. C. Sanders, D. Feder |

Slowing the probe field in the second window of double-double electromagnetically induced transparency University of Calgary | Publication | 2015-01-01 | H. M. Alotaibi, B. C. Sanders |

Ordered measurements of permutation-invariant qubit strings University of Calgary | Publication | 2011-01-01 | A. Hentschel, B. C. Sanders |

Quantum quincunx for walk on circles in phase space with indirect coin flip University of Calgary | Publication | 2008-01-01 | P. Xue, B. C. Sanders |

Marzlin and Sanders reply University of Calgary | Publication | 2006-01-01 | K. -. Marzlin, B. C. Sanders |

Optimal remote state preparation University of Calgary | Publication | 2003-01-01 | D. W. Berry, B. C. Sanders |

Non-Gaussian states of light as a resources for quantum information processing with continuous variables University of Calgary | Publication | 2005-01-01 | S. Ghose, B. C. Sanders |

Rigorous analysis of homodyne detection University of Calgary | Publication | 2003-01-01 | T. Tyc, B. C. Sanders |

Emission modes for superradiance and subradiance University of Calgary | Publication | 2003-01-01 | L. Horvath, B. C. Sanders, J. P. Clemens, H. J. Carmichael |

Quantum noise measurements of electron current via phase sensitive detection University of Calgary | Publication | 2003-01-01 | S. D. Bartlett, B. C. Sanders |

Relations between bosonic quadrature squeezing and atomic spin squeezing University of Calgary | Presentation | 2003-12-01 | G. X. Wang, B. C. Sanders |

Cavity modes of a planar microcavity University of Calgary | Presentation | 1999-07-07 | J. -. Shi, B. C. Sanders |

Preparation and assessment of non-Gaussian states of light as a resource for universal continuous variable quantum computation University of Calgary | Presentation | 2005-02-18 | S. Ghose, B. C. Sanders |

Learned feedback control mechanisms for a quantum systemThe talk presents an example based introduction on how machine learning can be applied to a quantum system. It starts with illustrating the main concepts of quantum information science and points out essential differences between classical and quantum systems, which are important in designing AI systems.
The main part of the talk is dedicated to the possible application of gravitational wave detection. It is illustrated how machine learning could potentially be used to control a quantum system, which is in our case, an interferometer for gravitational wave detection. It will be shown that in this context, the learning problem is related to learning a decision tree and how evolutionary algorithms could be applied in this particular case. University of Calgary | Presentation | 2008-08-12 | A. Hentschel, B. C. Sanders |

Measurement of a charge qubit with a nanocantilever University of Calgary | Presentation | 2008-08-20 | C. Wang, B. C. Sanders, P. Xue, P. W. Zhang |

Quantum states prepared by practical entanglement swappingEntanglement swapping between photon pairs is a fundamental building block
in schemes using quantum relays and quantum memories to overcome the range
limits of long distance quantum key distribution. We develop a closed-form
solution for the actual quantum states prepared by practical entanglement
swapping, which takes into account experimental deficiencies due to
inefficient detectors, detector dark counts and multi-photon-pair
contributions of parametric down conversion sources.
We investigate how the entanglement present in the final state
of the remaining modes is affected
by the practical imperfections. To test the predictions of our theory,
comparison with experimental entanglement swapping is provided.
University of Calgary, The University of Calgary | Presentation | 2009-02-20 | A. Scherer, B. C. Sanders, W. Tittel |

Quantum states prepared by real-world entanglement swapping and implications for Quantum Key DistributionEntanglement swapping between photon pairs is a fundamental building block
in schemes using quantum relays or quantum repeaters to overcome the range
limits of long distance quantum key distribution. We have developed a closed-form
solution for the actual quantum states prepared by realistic entanglement
swapping, which takes into account experimental deficiencies due to
inefficient detectors, detector dark counts and multi-photon-pair
contributions of parametric down conversion sources.
Using our theory, we investigate how the QBER and the Secret Key Rate
are affected by the real-world imperfections in a QKD experiment
based on a BBM92 protocol with a single practical entanglement
swapping. In particular, we provide the optimal photon-pair production
rate of parametric down conversion sources for a given distance between
Alice and Bob. University of Calgary, The University of Calgary | Presentation | 2009-08-21 | A. Scherer, B. C. Sanders, W. Tittel |

Monogamy of multi-qubit entanglement in terms of Rényi and Tsallis entropies University of Calgary | Presentation | 2010-08-27 | J. Kim, B. C. Sanders |

Storing a Microwave Pulse in Artificial Atoms with Electromagnetically Induced Transparency University of Calgary | Presentation | 2011-07-06 | P. M. Leung, B. C. Sanders |

Characterization of dangling-bond charge-qubit dynamics University of Calgary | Presentation | 2011-08-29 | Z. Shaterzadeh-Yazdi, B. C. Sanders |

Electromagnetic response properties of fluxonium atomElectromagnetic Response of Fluxonium.
Hessa M. Alotaibi1, 2, and Barry C. Sanders1
1Institute for Quantum Information Science, University of Calgary, Alberta T2N 1N4, Canada
2 Public Authority for Applied Education and Training, P.O. Box No. 23167, Safat 13092 Kuwait
Fluxonium is especially promising as an artificial atom in a superconducting circuit because it admits a few electronic levels with low loss and decoherence [1]. These advantages arise because fluxonium has a multiple well potential whose properties are controlled by an external magnetic field. Fluxonium has previously been shown to be capable of exhibiting electromagnetically induced transparency and a new phenomenon known as electromagnetically induced transparency with amplification by operating with three electronic levels [2]. We study the electromagnetic response properties of fluxonium, which has been engineered to have four well-behaved electronic levels.
Our theoretical analysis, based on solving density-matrix master equations with classical driving fields, shows two transparency windows in the spectral response profile with locations determined by detunings of the weak signal and strong driving fields. The strong driving field can also be used to control transparency window width, dispersion and group velocity of the pulse. In particular we show that a significant reduction of the group velocities and also matching of the group velocities of the two signal fields are achievable for strong driving fields in accordance with predictions for optical systems [3, 4]. We show that judiciously chosen control parameters such as driving field strength can yield the existence of a point in the spectrum where the transparency windows for the two weak fields coincide for slightly different energy detunings, which ensures that field nonlinearities do not vanish, thereby enabling cross-phase modulation of the two signal fields. These results could be valuable for applications to quantum memory and quantum phase gates.
[1] Vladimir E. Manucharyan, Jens Koch, Leonid I. Glazman, Michel H. Devoret, Science 326, 113 (2009).
[2] Jaewoo Joo, Jérôme Bourassa, Alexandre Blais, and Barry C. Sanders, Phys. Rev. Lett. 105, 073601 (2010).
[3] S. Rébic, D. Vitali, C. Ottaviani, P. Tombesi, M. Artoni, F. Cataliotti, and R. Corbalan, Phys. Rev. A. 70, 032317 (2004).
[4] Amitabh Joshi, and Min Xiao, Phys. Rev. A. 72, 062319 (2005).
University of Calgary | Presentation | 2012-06-12 | H. M. Alotaibi, B. C. Sanders |

An enhanced machine learning algorithm for precise adaptive phase estimationSequential adaptive measurement is a promising strategy for quantum-enhanced single-shot measurements, but appropriate adaptive procedures are difficult to devise even for ideal cases. Machine learning techniques enable suitable procedures to be found, but these machine learning methods are severely limited by computational time and space restrictions. Thus far the collective intelligence algorithm known as particle swarm optimization has been used to beat the best previous results (obtained by clever guessing) for adaptive phase measurement in quantum interferometry with an input state of an entangled multi-photon pulse. Specifically, particle swarm optimisation has successfully devised procedures with a space cost that is linear in the number N of operations on the multi-photon pulse and a time that scales as N6 [1, 2]. The resultant procedure delivers a power-law scaling for the interferometric phase uncertainty,\\r\\n∆¦Õ vs N, but this power law scaling breaks suddenly at an input N ¡Ö 50 due to a failure of the technique for specific computational resources, namely the number of particles (particle swarm optimisation candidate solutions) and number of iterations. We devise a far superior algorithm that is able to deliver much better precision for given N with the restriction of using the same computational resources as the competing algorithm. We show that the differential evolution approach to machine learning delivers this same power law scaling as particle swarm optimisation and shows no sign of breakdown up to one hundred photons. As the true cost scales as N6, this doubling (at least) of the number of photons actually corresponds to a 64 fold increase in the efficiency of devising the algorithm. University of Calgary | Presentation | 2012-12-17 | N. Lovett, B. C. Sanders |

Recovering quantum secrets via classical channelsQuantum secret sharing is an important multipartite cryptographic protocol in which a quantum state (secret) is shared among a set of n players. The secret is distributed in such a way that it can only be recovered by certain authorized subsets of players acting collaboratively. The recovery procedure assumes that all players are interconnected through quantum channels, or, equivalently, that the players are allowed to perform non-local quantum operations. However, for practical applications, the consumption of quantum communication resources such as entanglement or quantum channels needs to minimized.
We provide a novel scheme in which quantum communication is replaced by local operations and classical communication (LOCC). Our protocol is based on embedding a classical maximum distance separable (MDS) code into a quantum error correcting code and employing the properties of the latter. Our scheme is appealing for real-world scenarios where the implementation of two-qubit gates is challenging. We illustrate the results by simple examples. Our methods constitute a first step towards attacking the important problem of decoding quantum error correcting codes by LOCC.
*Collaboration with Barry C. Sanders.
We acknowledge support from the Natural Sciences and Engineering Research Council (NSERC) of Canada and from Paciﬁc Institute for Mathematical Sciences (PIMS).
University of Calgary | Presentation | 2013-02-21 | V. Gheorghiu, B. C. Sanders |

Recovering quantum information via classical channelsQuantum secret sharing is an important multipartite cryptographic protocol in which a quantum state\r\n(secret) is shared among a set of n players. The secret is distributed in such a way that it can only be\r\nrecovered by certain authorized subsets of players acting collaboratively. The recovery procedure assumes\r\nthat all players are interconnected through quantum channels, or, equivalently, that the players are allowed\r\nto perform non-local quantum operations. However, for practical applications, the consumption of quantum\r\ncommunication resources such as entanglement or quantum channels needs to minimized.\r\nWe provide a novel scheme in which quantum communication is replaced by local operations and classical\r\ncommunication (LOCC). Our protocol is based on embedding a classical maximum distance separable (MDS)\r\ncode into a quantum error correcting code and employing the properties of the latter. Our scheme is appealing\r\nfor real-world scenarios where the implementation of two-qubit gates is challenging. We illustrate the results\r\nby simple examples. Our methods constitute a rst step towards attacking the important problem of decoding\r\nquantum error correcting codes by LOCC. University of Calgary | Presentation | 2013-02-26 | V. Gheorghiu, B. C. Sanders |

Finite precision in Trotter-Suzuki decomposition University of Calgary | Presentation | 2013-06-06 | I. Dhand, B. C. Sanders |

Complementarity and quantum walks University of Calgary | Presentation | 2004-07-25 | V. Kendon, B. C. Sanders |

Analysis of non-Gaussian states of light as a resource for quantum information processing with continuous variables University of Calgary | Presentation | 2005-08-04 | S. Ghose, B. C. Sanders |

Atom interferometry, microscopy, complementarity, and the perfect lensDevelopment of the `perfect lens' poses an interesting challenge to standard concepts of complementarity manifested in interferometric which-way vs fringe visibility experiments. We show that a `microscope' with a `perfect lens' provides the extremal point of maximum which-way information in atom interferometry, and our theory rigorously connects complementarity in interferometry with the standard position-momentum Heisenberg uncertainty relation. University of Calgary | Presentation | 2007-06-09 | K. Marzlin, B. C. Sanders, L. P. Knight |

Real source quantum key distribution relaysWe have developed a model for relay-based quantum key distribution that incorporates multi-photon source events and dark counts at detectors. The model compares achievable quantum key distribution rates for configurations with different numbers of segments over a range of distances. Different photon source distributions and dark count rates are compared for given configurations to ascertain the impact of the source and detector imperfections on secure key rates. The University of Calgary, University of Calgary | Presentation | 2007-06-19 | W. Tittel, B. C. Sanders |

Artificial intelligence in a quantum worldThe talk presents one of the very first attempts to address the interdisciplinary challenge of combining the concept of artificial intelligence with the potentials of quantum information.
Some
The principled approach to machine learning is through a probabilistic viewpoint. A widely used formalism is Bayesian inference. This technique of belief revision is adapting the degree of belief in a hypothesis depending on the results of ongoing observations. University of Calgary | Presentation | 2008-06-19 | A. Hentschel, B. C. Sanders |

Quantum states after N concatenated entanglement swappings under real-world conditions University of Calgary | Presentation | 2009-05-25 | A. Scherer, B. C. Sanders |

On the geomatic distance between quantum states with positive partial transposition and private states University of Calgary | Presentation | 2009-08-27 | J. Kim, B. C. Sanders |

Feedback iterative decoding of sparse quantum codes University of Calgary | Presentation | 2009-08-29 | Y. Wang, B. C. Sanders, B. -. Bai, X. -. Wang |

Using machine learning for measuring and controlling quantum systemSuccess in reliably measuring and controlling quantum systems triggered many technological and scientific breakthroughs recently:
atomic clocks determine time via precise measurements of atomic oscillations; a pure quantum effect is used in current hard drives to read out the stored data; and gravitational wave detectors use interferometers to search for tiny deformations in space caused by gravitational waves.
At the fundamental level, measurement precision is limited by Heisenberg's uncertainty principle but even reaching a precision close to the Heisenberg bound is far beyond existing technology because of source and detector limitations. Adaptive measurement strategies are promising because they can greatly reduce the technological requirements.
However, finding good adaptive protocols, even for simple quantum systems, is very hard and often involves clever guesswork.
Fortunately, the area of artificial intelligence suggests a promising approach.
The advantage of machine learning is that the program learns from its
own performance and tries to devise better problem-solving strategies for the future.
In my talk, I will describe a way that machine learning can be used to devise adaptive quantum measurement and quantum control protocols. I will explain our technique using the example of measuring an interferometric phase shift, which is important for applications such as gravitational wave detection, where the wave imposes an unknown phase difference between the two arms of a Mach-Zehnder Interferometer.
University of Calgary | Presentation | 2009-06-25 | A. Hentschel, B. C. Sanders |

Monogamy of entanglement using Rényi and Tsallis University of Calgary | Presentation | 2010-08-24 | J. Kim, B. C. Sanders |

Superfluid to Mott-Insulator Transition in Thermodynamic Limit of 1D Coupled Cavity Array University of Calgary | Presentation | 2012-02-29 | A. D'Souza, B. C. Sanders, D. Feder |

Coupling of quantum fluctuations in a two-component condensateWe model frozen light stored via electromagnetically induced
transparency quantum-memory techniques in a Bose-Einstein
condensate. The joint evolution of the condensate and the frozen light is
typically modeled using coupled Gross-Pitaevskii equations for the two
atomic fields, but these equations are only valid in the mean-field limit.
Even when the mean-field limit holds individually for each atomic-field
component, coupling between the neglected fluctuations of the two
components could lead to a breakdown of the mean-field approximation
even if it is a good approximation for each species individually. We solve
and test the effect of coupled quantum fluctuations on coherent nonlinear
evolution of the frozen light pulse to see whether this two-species
condensate could enable nonlinear quantum optical phenomena.
Our analysis commences with a full second-quantized Hamiltonian
for a two-component condensate. The field operators are broken
up into a mean-field and a quantum fluctuation component. The
quantum fluctuations are truncated to lowest non-vanishing order.
The transformation diagonalizing the second-quantized approximate
Hamiltonian is described by coupled differential equations that are solved
with a power series expansion. We compare the consequent dynamics
with the mean-field evolution given by the two-component GrossPitaevskii equation. University of Calgary | Presentation | 2013-02-07 | C. Trail, B. C. Sanders |

Universal entanglement dynamics in quantum chaotic systemsWe identify and analyze universal features of entanglement dynamics in quantum systems that are classically chaotic. We derive an expression for the evolution of the linear entropy in terms of the decomposition of the initial state in the basis of eigenstates of the Hamiltonian and analyze the power spectrum of the entanglement dynamics. We apply our analysis to the quantum kicked top system and also present results for an experimentally accessible system of cold atoms in a magneto-optical lattice. The entanglement exhibits quasiperiodic behavior for states initially localized in a regular island. For states in the chaotic region, there is a rapid increase of entanglement and no quasiperiodic behavior. We show that these features are universal and a result of the support of the initial state on ‘regular’ or ‘chaotic’ eigenstates. We present a detailed analysis of the regular quasi-periodic dynamics and the chaotic dynamics. We also estimate the initial rapid increase in the entanglement and compare our estimate to a previous result using semiclassical methods.
University of Calgary | Presentation | 2004-05-27 | S. Ghose, B. C. Sanders, H. I. Deutsch |

Emission mode for superradiance and subradiance University of Calgary | Presentation | 2003-12-01 | L. Horvath, B. C. Sanders, P. J. Clemens, J. H. Carmichael |

Capacities of two-qubit unitary operations University of Calgary | Presentation | 2003-07-14 | W. D. Berry, B. C. Sanders |

Quantum noise measurements of electron states via phase sensitive detection University of Calgary | Presentation | 2003-02-17 | D. S. Bartlett, B. C. Sanders |

Quantum teleportation and entanglement swapping for systems of arbitrary spin University of Calgary | Presentation | 2001-12-05 | W. D. Berry, B. C. Sanders |

Quantum secret sharing with continuous variables University of Calgary | Presentation | 2001-10-06 | T. Tyc, B. C. Sanders |

Rigorous theory of quantum optical homodyne detection University of Calgary | Presentation | 2001-10-06 | T. Tyc, B. C. Sanders |

Optical continuous variable quantum teleportation: a convenient fiction University of Calgary | Presentation | 2001-01-21 | T. Rudolph, B. C. Sanders |

Requirement of optical nonlinearity for photon counting University of Calgary | Presentation | 2001-12-09 | D. S. Bartlett, B. C. Sanders |

Multiphoton coincidence spectroscopy University of Calgary | Presentation | 1998-12-14 | L. Horvath, B. C. Sanders, F. B. Wielinga |

Finite detection window in photon coincidence spectroscopy University of Calgary | Presentation | 1997-12-10 | L. Horvath, B. C. Sanders, F. B. Wielinga |

Quantum tunnelling of atoms through laser beams University of Calgary | Presentation | 1993-12-04 | P. W. Zhang, B. C. Sanders |

Off-line resource for universal continuous-variable quantum information processing University of Calgary | Presentation | 2005-03-01 | S. Ghose, B. C. Sanders |

When is teleportation quantum? University of Calgary | Presentation | 2005-05-11 | S. Bandyopadhyay, B. C. Sanders |

Low loss surface polaritons and quantum memory in meta-materials University of Calgary | Presentation | 2010-02-24 | A. Kamli, B. C. Sanders, S. Moiseev |

Extended Hubbard model simulations of charge-qubit circuits: from idealism to realismCharge qubits are promising quantum logical elements for performing quantum computation or as intermediate states to prepare and read other qubit realizations such as spin or flux. Instead of idealizing the charge qubits at the outset and using standard quantum circuit theory, we use the extended Hubbard model as a first-principles model of charge qubit dynamics and model idealized proposals for charge-qubit circuits using this second-quantized description with short- and medium-range interactions. In particular we study how one- and two-qubit gates would perform for realistic systems, and we apply our theory to teleportation of a single charge qubit in a three-qubit system. We also discuss how to incorporate phonon noise into the model. University of Calgary | Presentation | 2010-03-16 | Z. Shaterzadeh-Yazdi, B. C. Sanders |

Two electromagnetically induced transparency windows and cross-phase modulation with four-level superconducting artificial atomsSuperconducting circuit quantum electrodynamics (SCQED) employs microwave transmission lines coupled to artificial atoms, which are typical two-level and recently three-level for electromagnetically induced transparency (EIT). We propose SCQED with a four-level tripod-configuration artificial atom to enable cross-phase modulation between two traveling-wave microwave fields. Our master-equation analysis for three driving fields (``signal,'' ``probe'' and ``coupling'') demonstrates the existence of two distinct EIT transparency windows in the spectral-response profile as a function of coupling and weak fields strength. We provide the first theoretical analysis of this unexpected second window and show its advantages over the known first EIT window. Specifically we show that this second EIT window provides both the signal and probe fields with identical response functions provided that their Rabi frequencies and detunings are the same. Exploiting the second window with judiciously chosen external flux and energy detuning result in low absorption, excellent group velocity matching, and high nonlinearity, thereby enabling strong cross-phase modulation for SCQED. University of Calgary | Presentation | 2013-03-21 | H. M. Alotaibi, B. C. Sanders |

Tonks-Girardeau phase in 1D coupled cavity arrays University of Calgary | Presentation | 2012-05-29 | A. D'Souza, B. C. Sanders, D. Feder |

Optical quantum memory University of Calgary, The University of Calgary | Publication | 2009-01-01 | A. Lvovsky, B. C. Sanders, W. Tittel |

Quantum simulation of macro and micro quantum phase transition from paramagnetism to frustrated magnetism with a superconducting circuit University of Calgary | Publication | 2016-01-01 | J. Ghosh, B. C. Sanders |

Quantum circuit design for accurate simulation of qudit channels University of Calgary | Publication | 2015-01-01 | D. -. Wang, B. C. Sanders |

Bounding Quantum Gate Error Rate Based on Reported Average Fidelity University of Calgary | Publication | 2015-01-01 | Y. Sanders, B. C. Sanders |

An efficient algorithm for optimizing adaptive quantum metrology processes University of Calgary | Publication | 2011-01-01 | A. Hentschel, B. C. Sanders |

Monogamy of multi-qubit entanglement using Rényi entropy University of Calgary | Publication | 2010-01-01 | J. Kim, B. C. Sanders |

Algorithms for SU(n) boson realizations and D-functionsBoson realizations map operators and states of groups to transformations and states of bosonic systems. We devise a graph-theoretic algorithm to construct the boson realizations of the canonical SU(n) basis states, which reduce the canonical subgroup chain, for arbitrary n. The boson realizations are employed to construct -functions, which are the matrix elements of arbitrary irreducible representations, of SU(n) in the canonical basis. We demonstrate that our -function algorithm offers significant advantage over the two competing procedures, namely factorization and exponentiation. University of Calgary | Publication | 2015-01-01 | I. Dhand, B. C. Sanders, H. G. De |

Distributed Encryption Methods and Systems University of Calgary | Product | 2006-12-08 | T. Beals, B. C. Sanders |

Precise space-time positioning for entanglement harvesting University of Calgary | Publication | 2016-01-01 | E. Martín-Maríinez, B. C. Sanders |

Cooperative light scattering in any dimension University of Calgary | Publication | 2017-01-01 | T. Hill, B. C. Sanders, H. Deng |

Loophole-free Bell tests and the falsification of local realism University of Calgary | Publication | 2017-01-01 | P. Fraser, B. C. Sanders |

Detecting topological transitions in two dimensions by Hamiltonian evolution University of Calgary | Publication | 2017-01-01 | W. Zhang, B. C. Sanders, S. Apers, S. Goyal, D. Feder |

Spin Squeezing Criterion with Local Unitary Invariance University of Calgary | Publication | 2003-06-01 | A. R. Devi, X. Wang, B. C. Sanders |

Collective spontaneous emission from a line of atoms University of Calgary | Publication | 2003-08-01 | J. P. Clemens, L. Horvath, B. C. Sanders, H. J. Carmichael |

Efficient sharing of a continuous-variable quantum secret University of Calgary | Publication | 2003-06-01 | T. Tyc, D. J. Rowe, B. C. Sanders |

Separability criterion for separate quantum systems University of Calgary | Publication | 2003-05-01 | M. G. Raymer, A. C. Funk, B. C. Sanders, H. d. Guise |

Entanglement gauge and the non-Abelian geometric phase with two photonic qubits University of Calgary | Publication | 2003-02-01 | K. Marzlin, S. D. Bartlett, B. C. Sanders |

Quantum gates on hybrid qudits University of Calgary | Publication | 2003-02-01 | J. Daboul, X. Wang, B. C. Sanders |

Layer-by-layer photonic crystal horn antenna University of Calgary | Publication | 2004-09-01 | A. R. Weily, K. P. Esselle, B. C. Sanders |

Geometric phase for an adiabatically evolving open quantum system University of Calgary | Publication | 2004-10-01 | I. Kamleitner, J. D. Cresser, B. C. Sanders |

Creation of skyrmions in a spinor Bose-Einstein condensate University of Calgary | Publication | 2000-01-01 | K. -. Marzlin, W. Zhang, B. C. Sanders |

Entangled coherent-state qubits in an ion trap University of Calgary | Publication | 2000-10-01 | W. J. Munro, G. J. Milburn, B. C. Sanders |

Two-coherent-state interferometry University of Calgary | Publication | 2000-06-01 | D. A. Rice, G. Jaeger, B. C. Sanders |

Continuous-variable quantum teleportation of entanglement University of Calgary | Publication | 2002-10-01 | T. J. Johnson, S. D. Bartlett, B. C. Sanders |

Quantum dynamics of two coupled qubits University of Calgary | Publication | 2002-02-01 | G. J. Milburn, R. Laflamme, B. C. Sanders, E. Knill |

Entanglement as a signature of quantum chaos University of Calgary | Publication | 2004-07-01 | X. Wang, S. Ghose, B. C. Sanders, B. Hu |

Shot-to-shot fluctuations in the directed superradiant emission from extended atomic samples University of Calgary | Publication | 2004-07-01 | J. P. Clemens, L. Horvath, B. C. Sanders, H. J. Carmichael |

Asymptotic limits of SU(2) and SU(3) Wigner functions University of Calgary | Publication | 2001-01-01 | D. J. Rowe, H. d. Guise, B. C. Sanders |

Unitary transformations for testing Bell inequalities University of Calgary | Publication | 2001-03-01 | S. D. Bartlett, D. A. Rice, B. C. Sanders, J. Daboul, H. d. Guise |

Correlation effects in a discrete quantum random walk University of Calgary | Publication | 2009-01-01 | J. Stang, A. Rezakhani, B. C. Sanders |

Accelerated guided atomic pulse University of Calgary | Publication | 1997-09-01 | S. Dyrting, W. Zhang, B. C. Sanders |

Resonant atomic tunneling through a laser beam University of Calgary | Publication | 1996-12-01 | L. Tribe, W. Zhang, B. C. Sanders |

Photon Correlation Spectroscopy University of Calgary | Publication | 1996-07-01 | H. J. Carmichael, P. Kochan, B. C. Sanders |

Entanglement and the quantum-to-classical transition University of Calgary | Publication | 2005-07-01 | S. Ghose, P. M. Alsing, B. C. Sanders, I. H. Deutsch |

Deterministic entanglement of assistance and monogamy constraints University of California, San Diego, University of Calgary | Publication | 2005-10-01 | G. Gour, D. A. Meyer, B. C. Sanders |

No Approximate Complex Fermion Coherent States University of Calgary | Publication | 2007-05-01 | T. Tyc, B. Hamilton, B. C. Sanders, W. D. Oliver |

Double electromagnetically induced transparency and its application in quantum information University of Calgary | Publication | 2006-08-01 | Z. Wang, K. Marzlin, B. C. Sanders |

Three-mode squeezing: SU(1,1) symmetry University of Calgary | Publication | 2007-06-01 | Z. S. Yazdi, P. S. Turner, B. C. Sanders |

On the epistemic view of quantum states University of Calgary | Publication | 2008-01-01 | M. Skotiniotis, A. Roy, B. C. Sanders |

Strong terahertz emission from superlattices via Zener tunneling University of Calgary | Publication | 2007-06-01 | P. Han, K. Jin, B. C. Sanders, Y. Zhou, H. Lu, G. Yang |

SU(1,1) symmetry of multimode squeezed states University of Calgary | Publication | 2008-01-01 | Z. Shaterzadeh-Yazdi, P. Turner, B. C. Sanders |

Criteria for dynamically stable decoherence-free subspaces and incoherently generated coherences University of Calgary | Publication | 2008-01-01 | R. Karasik, K. -. Marzlin, B. C. Sanders, K. Whaley |

Distributed authentication for randomly compromised networks University of Calgary | Publication | 2009-01-01 | T. Beals, K. Hynes, B. C. Sanders |

Tripartite entanglement dynamics for an atom interacting with nonlinear couplers University of Calgary | Publication | 2009-01-01 | M. Abdel-Aty, M. S. Abdalla, B. C. Sanders |

Limitations on continuous variable quantum algorithms with Fourier transforms University of Calgary | Publication | 2009-01-01 | M. Adcock, P. Høyer, B. C. Sanders |

Distribution and dynamics of entanglement in high-dimensional quantum systems using convex-roof extended negativity University of Alberta, University of Calgary | Publication | 2011-01-01 | S. Lee, J. Kim, B. C. Sanders |

Superradiance, subradiance, and suppressed superradiance of dipoles near a metal interface University of Calgary | Publication | 2010-01-01 | J. Choquette, K. -. Marzlin, B. C. Sanders |

Objectively discerning Autler-Townes splitting from electromagnetically induced transparency University of Calgary | Publication | 2011-01-01 | P. Anisimov, J. Dowling, B. C. Sanders |

Constructing monotones for quantum phase references in totally dephasing channels University of Calgary | Publication | 2011-01-01 | B. Toloui Semnani, G. Gour, B. C. Sanders |

Quantum-circuit design for efficient simulations of many-body quantum dynamics University of Calgary | Publication | 2012-01-01 | S. Raeisi, N. Wiebe, B. C. Sanders |

Limitations to sharing entanglement University of Calgary | Publication | 2012-01-01 | J. Kim, G. Gour, B. C. Sanders |

Two coupled Jaynes-Cummings cells University of Calgary | Publication | 2011-08-01 | P. Xue, Z. Ficek, B. C. Sanders |

Low-loss surface modes and lossy hybrid modes in metamaterial waveguides University of Calgary | Publication | 2012-01-01 | B. Lavoie, P. M. Leung, B. C. Sanders |

Gaussian quantum computation with oracle-decision problems University of Calgary | Publication | 2013-01-01 | M. Adcock, P. Høyer, B. C. Sanders |

Slow light with three-level atoms in metamaterial waveguides University of Calgary | Publication | 2013-01-01 | B. Lavoie, P. M. Leung, B. C. Sanders |

Practical long-distance quantum communication using concatenated entanglement swapping University of Calgary, The University of Calgary | Publication | 2013-01-01 | A. Khalique, W. Tittel, B. C. Sanders |

High-Fidelity Single-Shot Toffoli Gate via Quantum Control University of Calgary | Publication | 2015-01-01 | E. Zahedinejad, J. Ghosh, B. C. Sanders |

A heralded two-qutrit entangled state University of Calgary | Publication | 2009-01-01 | J. Joo, T. Rudolph, B. C. Sanders |

Degradation of a quantum directional reference frame as a random walk University of Calgary | Publication | 2007-01-01 | S. D. Bartlett, T. Rudolph, B. C. Sanders, P. Turner |

Duality for monogamy of entanglement University of Calgary | Publication | 2007-01-01 | G. Gour, S. Bandyopadhyay, B. C. Sanders |

Optimal fingerprinting strategies with one-sided error University of Calgary | Publication | 2007-01-01 | A. Scott, J. Walgate, B. C. Sanders |

Efficiency limits for linear optical processing of single photons and single-rail qubits University of Calgary | Publication | 2007-01-01 | D. W. Berry, A. Lvovsky, B. C. Sanders |

Large cross-phase modulation between slow co-propagating weak pulses in 87Rb University of Calgary | Publication | 2006-01-01 | Z. -. Wang, K. -. Marzlin, B. C. Sanders |

Interconvertibility of single-rail optical qubits University of Calgary | Publication | 2006-01-01 | D. W. Berry, A. Lvovsky, B. C. Sanders |

Improving single-photon sources via linear optics and photodetection University of Calgary | Publication | 2004-01-01 | D. W. Berry, S. Scheel, B. C. Sanders, P. L. Knight |

Photonic crystal horn and array antennas University of Calgary | Publication | 2003-01-01 | A. R. Weily, K. P. Esselle, B. C. Sanders |

Multipartite entangled states in coupled quantum dots and cavity QED University of Calgary | Publication | 2003-01-01 | X. G. Wang, M. Feng, B. C. Sanders |

Spin squeezing criterion with local unitary operators University of Calgary | Publication | 2003-01-01 | A. R. Devi, X. G. Wang, B. C. Sanders |

Three-mode squeezing: SU(1,1) symmetry University of Calgary | Publication | 2007-01-01 | Z. Shaterzadeh-Yazdi, P. Turner, B. C. Sanders |

Ku band electromagnetic bandgap antennas University of Calgary | Publication | 2006-01-01 | A. R. Weily, K. P. Esselle, B. C. Sanders, T. S. Bird |

Woodpile EBG Resonator and aperture Antennas University of Calgary | Publication | 2005-01-01 | A. R. Weily, K. P. Esselle, B. C. Sanders, T. S. Bird |

Collective spontaneous emission from small assemblies of atoms University of Calgary | Publication | 2003-05-01 | J. P. Clemens, L. Horvath, B. C. Sanders, H. J. Carmichael |

Multi-mode character of superradiant emission from 3D extended sources University of Calgary | Presentation | 2005-12-05 | L. Horvath, P. J. Clemens, B. C. Sanders, J. H. Carmichael |

Geometric phase of a system coupled to a reservoir, University of Calgary | Presentation | 2004-06-14 | K. Marzlin, S. Ghose, B. C. Sanders |

Giant nonlinearities and double electromagnetically induced transparency in Rb University of Calgary | Presentation | 2006-02-25 | Z. Wang, K. Marzlin, B. C. Sanders |

Theoretical and experimental research on photonic crystals at Macquarie University University of Calgary | Presentation | 2002-07-15 | R. A. Weily, P. K. Esselle, B. C. Sanders |

Interference between colliding Bose condensates in two dimensions University of Calgary | Presentation | 1999-07-07 | L. Tribe, P. W. Zhang, B. C. Sanders |

Rapid control and measurement of qubits in atomic Yb and Sr University of Calgary | Presentation | 2006-05-24 | N. Babcock, R. Stock, B. C. Sanders, M. A. Dudarev, G. M. Raizen |

A three boson su(1,1) realisation for linear optical quantum information University of Calgary | Presentation | 2006-07-25 | Z. Shaterzadeh-Yazdi, P. Turner, B. C. Sanders |

Discerning thermal properties of entanglement in qubit rings using n-concurrenceWe show that n-concurrence is an excellent tool for discerning the entanglemnet properties of qubit networks (e.g. rings) and demonstrate multiple entanglement revivals as temperature increses. University of Calgary | Presentation | 2007-06-07 | Y. Sanders, H. Carteret, B. C. Sanders |

Entangling neutral atoms in optical dipole trapsTrapped neutral atoms are promising candidates for performing quantum computations since they have long decoherence times and can easily be interfaced with light for single-qubit operations and measurements. We propose a method for entangling a pair of indistinguishable neutral atoms stored in separated optical dipole traps. We model this trapping potential in one dimension as a pair of Gaussian wells that can be brought together for atoms to interact. The dynamics of this process depend on the symmetrizations of the atomic subsystems. By choosing the correct interaction time a controlled-phase gate can be designed. Adiabatic separation guarantees that the atoms end up in opposite traps. We provide both adiabatic and time-dependent numerical simulations of the entangling process. Additionally, we consider a novel method for creating entangled qubits via selective excitation of atoms in an optical dipole trap.
University of Calgary | Presentation | 2007-06-02 | N. Babcock, R. Stock, B. C. Sanders, G. M. Raizen |

Refractive index of driven dense atomic gasesThe optical properties of an atomic gas, including
the dramatic reduction of the group velocity
of light associated with electromagnetically induced
transparency (EIT), usually grow with the density
of atoms in the medium. However, in high density
atomic gases, the resonant dipole-dipole interaction
(DDI) generates atomic correlations. These correlations
could significantly modify both linear and nonlinear
optical properties of the medium [1, 2, 3], which
may be beneficial for quantum information processing.
We develop a theory that describes the influence
of DDI on the optical properties of a dense gas
driven by classical control fields. Our method combines
dressed-states of quantum optics with nonequilibrium
many-body theory based on Feynman diagrams
and includes the effect of the atomic centerof-
mass-motion, which is relevant for the study of
different temperature regimes. This approach has
the advantage that the control fields are treated nonperturbatively. University of Calgary | Presentation | 2008-08-23 | I. Mahmoud, K. Marzlin, B. C. Sanders |

Control of slow surface polaritons in left-handed materials University of Calgary | Presentation | 2008-08-21 | S. Moiseev, A. Kamli, B. C. Sanders |

Secret sharing using graph states University of Calgary | Presentation | 2008-08-20 | D. Markham, A. Roy, B. C. Sanders |

Distribution and dynamics of entanglement University of Alberta, University of Calgary | Presentation | 2009-11-10 | S. Lee, J. Kim, B. C. Sanders |

Mixed state quantum reference frame resourcesSituations where the operations of a noisy channel used for the transmission and retrieval of quantum states belong to a specific group of transformations give rise to resources beside entanglement that allow us to overcome the ensuing constraints, such as when shared reference frames (RF) associated with symmetry groups are lacking between the nodes of a quantum channel. So far, most work on this new kind of resource, dubbed "frameness", has been focused on pure state transformations even though almost all states and operations in the lab involve some degree of mixedness. Here we address the problem of quantifying the frameness of mixed states. We introduce a new family of pure state frameness measures associated with Abelian Lie groups in a Hilbert space of arbitrary but finite dimensions, whose convex roof extensions remain monotonic. In particular, we show that this family of frameness monotones are closely related to generalized concurrence functions of the reduced density operators of entangled states. This highlights interesting and deep links between frameness and entanglement resource theories, and provides a new way of classifying all frameness monotones as functions of the "twirled" state that results from tracing out the RF, where the state plus the RF are treated as a joint entangled system. Finally, we use a member of this family of frameness monotones to determine the explicit analytical form of a qubit's frameness of formation. The frameness of formation denotes the minimum average cost of preparing the ensemble of pure states that realize a given mixed state, and can be used to quantify the frameness of that state under certain conditions. Our results thus extends Wootter's formula for the entanglement of formation of bipartite qubit states to a whole new and different class of resources. University of Calgary | Presentation | 2010-02-19 | B. Toloui Semnani, G. Gour, B. C. Sanders |

Going beyond the share size bound in quantum secret sharingQuantum secret sharing (QSS) is an important cryptographic protocol which allows a quantum secret to be split between multiple "players", such that only certain authorised player subsets may recover the secret. It is, however, costly in terms of quantum communication and storage; perfect QSS using quantum states requires every player's share to be at least as large as the original secret.
I will discuss some of our recent results in which we improve upon this bound through the use of imperfect "ramp" secret sharing, which allows for smaller shares at the cost of weaker security. We find a specific class of "entanglement sharing" ramp protocols, which allow for smaller shares while still broadly restricting the protocols' information leakage.
Finally I will demonstrate how, by incorporating classical encryption into "hybrid" QSS protocols, quantum share size can be reduced (sometimes
drastically) without requiring any reduction in security.
University of Calgary | Presentation | 2011-06-28 | B. Fortescue, G. Gour, B. C. Sanders |

Measures For Quantum Reference Frame Resources And Their Link To Entanglement Monotones University of Calgary | Presentation | 2011-07-06 | B. Toloui Semnani, G. Gour, B. C. Sanders |

Metamaterial Waveguides University of Calgary | Presentation | 2011-08-29 | B. Lavoie, P. M. Leung, B. C. Sanders |

All-optical control in metamaterial-dielectric waveguidesWe explore the possibility of all-optical control of weak signals in waveguides having a dielectric core and a metamaterial cladding (metamaterial-dielectric waveguide). To this end we present a characterization of slab and cylindrical metamaterial-dielectric waveguides. To describe the permittivity of the metamaterial we use the lossy Drude model and for the permeability we use a lossy Lorentz-Drude model. We find that metamaterial-dielectric waveguides support modes with lower attenuation than metal-dielectric guides through expulsion of the fields from the metamaterial. The field expulsion also provides good transverse confinement in the cylindrical guide.
We propose using slow light to effect all-optical control in metamaterial waveguides. To slow the light, we employ electromagnetically induced transparency by pumping, with a strong control field, 3-level atoms embedded in the dielectric core. Pumping the atoms using a waveguide mode elicits a nonlinear response that results in a spatially graded refractive index in the core of the guide. The resulting refractive index depends on the strength and the transverse profile of the control field. We use the results of the aforementioned characterization to determine the properties of the control field (e.g. transverse profile). A signal field can then be manipulated by changing the parameters of the control field. All-optical control schemes, such as this, could be exploited for ultra-fast optical switches or quantum information processing applications. University of Calgary | Presentation | 2012-06-12 | B. Lavoie, P. M. Leung, B. C. Sanders |

Integrating out the quantum nature of electron transfer processes at the macromolecular scales University of Calgary | Presentation | 2012-10-08 | A. l. De, N. Babcock, B. C. Sanders, D. Salahub, E. H. El, C. Houée-Levin, B. Lévy, I. Demachy |

Learning algorithms for designing efficient, precise, robust, single-shot, quantum-enhanced adaptive parameter estimation policiesSequential adaptive measurement is a promising strategy for quantum-enhanced single-shot measurements, but appropriate adaptive procedures are difficult to devise even for ideal cases. Machine-learning techniques enable suitable adaptive policies to be found, but these machine-learning methods are severely limited by computational time and space restrictions. Thus far the collective-intelligence algorithm known as particle swarm optimization has been used to beat the best previous results (obtained by clever guessing) for single-shot adaptive quantum-enhanced measurements of interferometric phase measurement with an entangled multi-photon pulse input state. Specifically, particle swarm optimization previously yielded policies with a space cost that is linear in the number N of operations on the multi-photon pulse and a time that scales as N6 [1-3].
The resultant policy delivers a power-law scaling for the interferometric phase uncertainty phase, ∆φ vs N, but this power law scaling breaks suddenly at N~50 due to a failure of the technique for specific computational resources, namely the number of particles (particle swarm optimization candidate solutions) and number of iterations. Here we devise a far superior algorithm that is able to deliver much better precision for given N with the restriction of using the same computational resources as the competing algorithm. We show that the differential evolution approach to machine learning delivers this same power law scaling as particle swarm optimization and shows no sign of breakdown up to N=100 photons. As the true cost scales as N6, this doubling (at least) of the number of photons actually corresponds to a 64-fold increase in the efficiency of devising the algorithm.
University of Calgary | Presentation | 2013-02-26 | C. Crosnier, N. Lovett, B. C. Sanders |

Decoherence-free subspaces and spontaneous emission cancellation: necessity of Dicke limitDecoherence-free subspaces (DFS) of an open quantum system are states for which the coupling to the environment is canceled by destructive interference. DFS are usually studied for states involving two or more particles and are considered a prominent candidate for quantum memory and quantum information processing. Experiments with ions indicate that partial cancellation is possible, but a demonstration of significant cancellation is challenging. \\ We prove that a perfect physical DFS requires co-located particles, i.e., the Dicke limit. The assumptions made are very general and invoke a homogeneous environment with energy-conserving coupling to the particles. We indicate when a DFS outside the Dicke limit may be possible; this includes molecular and confined systems. Furthermore, we establish a connection between DFS and spontaneous emission cancelation and refine the conditions for one of the important theorems on DFS to hold. University of Calgary | Presentation | 2006-05-20 | K. Marzlin, R. Karasik, B. C. Sanders, B. K. Whaley |

Criteria for the existence of decoherence-free subspacesDecoherence-free subspaces (DFS) are spanned by such states of an open quantum system that are insensitive to the decoherence induced by the reservoir to which the system is coupled. DFS are immune to this coupling because of different physical effects, including destructive interference between different transition amplitudes or energy conservation.
We compare different definitions of DFS and explore rigorous criteria for the existence of DFS in finite-dimensional systems coupled to Markovian reservoirs. The advantages and disadvantages of various approaches are compared and a geometrical interpretation for DFS in qubit-systems is given.
University of Calgary | Presentation | 2007-06-01 | K. Marzlin, R. Karasik, B. C. Sanders, B. K. Whaley |

Criteria for dynamically stable decoherence-free subspacesA decoherence-free subspace (DFS) is a collection of states for a system that is impervious to dominant noise effects created by the environment. The DFS approach provides an important strategy for quantum information processing because it would allow quantum circuit simplification by reducing the need for quantum error correction and providing stable quantum memory. Experimental demonstrations of DFSs show the efficacy of this approach. We analyze similarities and differences between various approaches to DFSs present in the literature and show that an excessively restrictive assumption on immunity from decoherence for an arbitrary initial environment state can be relaxed for practical DFS cases. In the important class of systems whose dynamics is described by Markovian master equations, we provide necessary and sufficient conditions for the existence of a dynamically stable DFS. We also present examples that show why previous work in this direction was not sufficient. University of Calgary | Presentation | 2007-06-07 | R. Karasik, K. Marzlin, B. C. Sanders, B. K. Whaley |

A new approach to mutlipartite squeezed statesAn efficient technique to characterize complex linear quantum optical networks comprised by passive and active optical devices is the use of the symplectic Lie group, Sp(2n, R). Such optical networks play a significant role in the context of quantum information processing, and have been used in a variety of quantum schemes such as quantum teleportation [1] and quantum state/secret sharing [2]. In general, the operation of a multiport network of this type on a Gaussian input state can be described by Sp(2n, R) transformations, which preserve Gaussian states. The key tool in such quantum optical experiments is the generation and application of squeezed states. Recently, three-mode squeezed states have been produced in several quantum schemes. For characterizing such schemes, we have established a three-mode realization of SU(1, 1), which is a subgroup of Sp(6, R), and consequently the three-mode squeezed states are the coherent states of SU(1, 1). The elegance of this approach helps us to generalize it to multi-mode realizations of SU(1, 1), and to use them for characterizing any multiport quantum optical network constructed by concatenating sections, each with one two-mode squeezer and several passive optical devices. Such realizations give us a new insight into the interesting properties of the multimode squeezed states generated by any complex quantum optical network of this type. References: [1] N. Takei et al., Phys. Rev. A, 72, 042304 (2005). [2] A.M. Lance et al, Phys. Rev. A, 92, 177903 (2004).\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\n\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\r\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\n 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This work is being supported by iCORE University of Calgary | Presentation | 2007-06-19 | Z. Shaterzadeh-Yazdi, P. Turner, B. C. Sanders |

Multi-partite squeezed states and SU(1,1) symmetryOne goal of quantum information science is quantum information processing using complex quantum optical networks comprising passive and active linear optical elements, such as beam splitters and squeezers. Such networks can be described mathematically as Sp(2n, R) transformations on n modes, which correspond to mappings that preserve Gaussian states.
Recently, tripartite squeezed states have been produced experimentally and are quite useful for quantum information tasks such as quantum state sharing and quantum teleportation. Theoretically, such states have been characterized based on the type of input states, but we have developed a simple and elegant mathematical framework, which is three-boson realization of SU(1, 1), and characterized all squeezed states of this type as SU(1, 1) coherent states. Inspired by the elegance of this theory, we have generalized it to multiboson realization of SU(1, 1) that characterizes any multi-port linear optical system constructed from a two-mode squeezer and several passive optical elements, or by concatenating such multi-port systems to each other. Thus, this theory gives us new insight into the properties of a large class of multipartite squeezed states generated in any complex optical network with concatenated sections each with one two-mode squeezer.
University of Calgary | Presentation | 2007-09-09 | Z. Shaterzadeh-Yazdi, P. Turner, B. C. Sanders |

Fully epistemic toy theoryThe Spekkens toy model is an interesting example of how to modify classical physics in order to perform several quantum information processing tasks. Spekkens\' toy model has four axioms concerning toy states, valid operations, measurements, and composition of single toy systems. Motivated by the empirical indistinguishability of epistemic vs. ontic states in the toy universe, we show that relaxing valid operations to mappings of epistemic rather than ontic states preserves the features of the toy model. Similarly we show that relaxing the axiom regarding the composition of single toy systems also preserves the toy model. Relaxing both axioms simultaneously, however, breaks the correspondence of the toy model with quantum theory because the tensor product composition rule is violated, but these two relaxations together produce a group of operations on epistemic states that is isomorphic to the projected extended Clifford Group. University of Calgary | Presentation | 2008-03-11 | M. Skotiniotis, A. Roy, B. C. Sanders |

Atomic many-body effects in the propagation of slow light through atomic gasesA quantum memory for photonic qubits is an essential tool
for quantum information processing because it would be vital
for long-distance quantum communication. A strong candidate
for quantum memories are atomic gases that exhibit electromagnetically
induced transparency (EIT). In such a medium the information about a
photon can be reversibly stored in form of a spin-wave.
The common quantum optical calculations suggest that ultracold gases
of high density would be most suitable for this task, but these theories
ignore the dipole-dipole interaction (DDI) between atoms that become
relevant at high densities. We have investigated the effect of DDI on
EIT and found significant differences between hot and ultracold atomic
gases. In a dense gas bosonic atoms close to condensation, DDI changes
the refractive index more significantly and also leads to collective
decoherence effects. Our theoretical approach combines dressed-states
of quantum optics with non-equilibrium many-body techniques
(Keldysh diagrams). University of Calgary | Presentation | 2008-04-20 | K. Marzlin, I. Mahmoud, B. C. Sanders |

Collective excitation of surface plasmons by a linear dipole arraySurface plasmons are electromagnetically induced charge-density waves that appear at the interface between dielectrics and a thin metal film and can enhance optical field intensities by two to three orders of magnitude. Optical dipoles placed near the metal interface have their radiative properties significantly affected by the presence of surface plasmon modes. The spontaneous emission rate is heavily modified and an optical emitter can decay both radiatively and into a surface plasmon. We consider a linear (pencil-like) arrangement of $N$ dipoles in vacuum near a metal film on the surface of a prism. In free space this arrangement would predominantly emit radiation along the axis of this pencil with an intensity that increases like $N^2$. We show that this gain persists in the presence of the metal film and an additional enhancement of the intensity can be achieved by the narrow characteristic of the radiation field emitted by the induced surface plasmon modes. This effect is rather insensitive to the alignment of the pencil due to the evanescent nature of surface plasmon fields.
University of Calgary | Presentation | 2008-05-30 | J. Choquette, K. Marzlin, B. C. Sanders |

Multi-particle decoherence free subspaces in extended systemsA decoherence-free subspace (DFS) is a collection of states that are immune to the noise derived from interactions with the environment. DFS is especially of interest for states involving two or more particles and is considered a prominent candidate for quantum memory and quantum information processing. We develop a method for finding DFS in real quantum systems. For systems with a homogeneous environment and energy-conserving coupling to the particles in 3D space, our methods show that perfect DFS exists for co-located particles only . This restriction does not exist for confined systems, such as atoms embedded in an optical fiber.
University of Calgary | Presentation | 2008-05-29 | R. Karasik, K. Marzlin, B. C. Sanders, B. K. Whaley |

Surface polariton-polariton induced transparency in left-handed materials We propose to control surface polariton (SP) propagation in left-handed materials. New spectral behaviour of SP propagation is demonstrated due to the spatial properties of interaction between the SP modes and three level atoms. University of Calgary | Presentation | 2008-07-14 | A. Kamli, S. Moiseev, B. C. Sanders |

Non-locality tests for an optical two-qudit state University of Calgary | Presentation | 2008-08-28 | J. Joo, T. Rudolph, B. C. Sanders |

Resource theories, SU(2) super selection rule, and time inversion University of Calgary | Presentation | 2008-08-24 | G. Gour, W. R. Spekkens, B. C. Sanders, P. Turner |

Coherent control of low loss surface polaritons We propose fast all-optical control of surface polaritons by placing an electromagnetically induced transparency (EIT) medium at an interface between two materials. EIT provides longitudinal compression and a slow group velocity, while matching properties of the two materials at the interface provides strong transverse confinement. In particular, we show that an EIT medium near the interface between a dielectric and a negative-index metamaterial can establish tight longitudinal and transverse confinement plus extreme slowing of surface polaritons while simultaneously avoiding losses. University of Calgary | Presentation | 2009-07-13 | S. Moiseev, A. Kamli, B. C. Sanders |

Quantum secret sharing with qudit graph statesWe present a formalism for quantum secret sharing using graph states of systems with prime dimension. As we show, such states allow for a unified structure for the sharing of classical and quantum secrets over both classical and quantum channels. We give explicit protocols for three varieties of threshold secret sharing within this formalism. Joint work with Adrian Keet and Barry C. Sanders. University of Calgary | Presentation | 2010-02-20 | B. Fortescue, A. Keet, B. C. Sanders, D. Markham |

Waveguide characteristics for arbitrary permittivity and permeability including for metamaterials University of Calgary | Presentation | 2011-08-25 | B. Lavoie, P. M. Leung, B. C. Sanders |

Fermionized photons in one-dimensional coupled cavitiesWe consider the properties of a one-dimensional array of evanescently coupled high-finesse cavities each containing a single neutral atom, in the limit of low photon densities. The ground state of the corresponding Jaynes-Cummings-Hubbard (JCH) model is obtained numerically using the Density Matrix Renormalization Group algorithm. We find strong evidence for the existence of a Tonks-Girardeau phase, in which the photons are strongly fermionized, between the Mott-insulating and superfluid phases as a function of the inter-cavity coupling. Results for photon and spin excitation densities, one- and two-body correlation functions, and superfluid and condensate fractions are all found to be consistent with this conclusion. University of Calgary | Presentation | 2014-03-05 | D. Feder, A. D'Souza, B. C. Sanders |

Output couplers for 3D photonic crystal waveguides University of Calgary | Presentation | 2005-01-31 | R. A. Weily, P. K. Esselle, B. C. Sanders |

Quantum logic in a decoherence-suppressed subspace with atomic qubits University of Calgary | Presentation | 2005-01-31 | G. P. Brooke, K. Marzlin, B. C. Sanders |

Tripartite entangement of a trapped atom in an optical cavity University of Calgary | Presentation | 2004-06-16 | J. T. Harmon, R. Thompson, B. C. Sanders |

Entanglement gauge and non-abelian geometric phase for photonic qubits University of Calgary | Presentation | 2003-03-01 | K. Marzlin, D. S. Bartlett, B. C. Sanders |

Electromagnetic bandgap resonator antenna fed by a microstrip patch University of Calgary | Presentation | 2003-02-12 | R. A. Weily, P. K. Esselle, B. C. Sanders, S. T. Bird |

Three dimensional photonic crystal resonator antenna University of Calgary | Presentation | 2002-08-19 | R. A. Weily, P. K. Esselle, B. C. Sanders, S. T. Bird |

Unitary transformation for testing bell inequalities University of Calgary | Presentation | 2001-01-21 | D. S. Bartlett, A. D. Rice, B. C. Sanders, J. Daboul, H. G. De |

Erzeugung von skyrmionen in einem drei-komponentigen Bose-Einstein-Kondensat University of Calgary | Presentation | 2000-04-01 | K. Marzlin, P. W. Zhang, B. C. Sanders |

Quantum memory for surface polaritons in metamaterialsUnlike conventional materials, negative index meta-materials (NIMM) support both electric and magnetic surface polariton (SP) modes that are spatially confined to the media interface with highly reduced losses. We study electromagnetically induced transparency(EIT) based quantum control of SP modes in metamaterial structure. Utilizing SP confinement,\r\nwe demonstrate the possibility of low loss surface polariton fields with very slow group velocity at EIT conditions. We discuss potential applications in quantum information and quantum memory of weak light fields. University of Calgary | Presentation | 2009-05-24 | A. Kamli, S. Moiseev, B. C. Sanders |

Frameness of formation for a qubitAlmost all states and operations in the lab involve some degree of mixedness, so it is necessary to extend the results of the newly developed reference frame resource theories to include mixed states. We produce, for the first time, explicit results for a qubit's frameness of formation. The frameness of formation denotes the average resource cost of generating a mixed state. This cost is measured in terms of standard resource states, called refbits, that are chosen as units of frameness. In order to determine the exact value of this frameness measure, we develop a novel technique that generalizes Wootter's idea for entanglement of formation to a wide class of reference frame resource theories. We introduce the "concurrence of frameness" as a generalization of the concurrence measure to the case of reference frames. The concurrence of a resource state is explicitly determined, and the cost of preparing a resource is expressed as a simple function of this concurrence. This approach is applicable to resource measures of any given group of transformations associated with a superselection rule, as long as the related resource cost can be written as an explicit function of the concurrence of frameness. Finally, we demonstrate the application of our result to the resource theories of the groups Z_2 and U(1) that are associated with chiral and phase reference frames respectively. University of Calgary | Presentation | 2009-08-23 | B. Toloui Semnani, G. Gour, B. C. Sanders |

Quantum algorithms with continuous variables for black box problems University of Calgary | Presentation | 2010-08-30 | N. Cerf, M. Loïck, B. C. Sanders |

Cooperative effects for Qubits in a Transmission Line: Theory University of Calgary | Presentation | 2012-03-02 | K. Lalumière, A. Blais, B. C. Sanders, F. L. Van, A. Fedorov, A. Wallraff |

Tuning from coherent interaction to super- and subradiance with artificial atoms in a 1D waveguideTaking advantage of the near ideal spatial mode-matching, strong interaction between light and artificial atoms fabricated in a 1D waveguide has been demonstrated experimentally [1]. Here, we study the situation where multiple and possibly un-identical atoms are fabricated in the same waveguide. We find that atom relaxation and Lamb-shift are modified, leading to collective effects. Depending on the distance between the artificial atoms, or equivalently the phase shift accumulated by light traveling from one atom to another, we find that it is possible to tune between a strong modification of individual atomic relaxation with the formation of sub- and superradiant states, and a strong modification of the Lamb-shift leading to a coherent exchange-type interaction between the atoms. These predictions are based on a master equation derived for an inhomogeneous set of atoms coupled to a transmission line. Comparison with experimental results will be discussed. University of Calgary | Presentation | 2013-03-21 | K. Lalumière, A. Blais, B. C. Sanders, F. L. Van, A. Fedorov, A. Wallraff |

Cooperative effects for qubits in a transmission line: theory University of Calgary | Publication | 2012-03-01 | K. Lalumière, A. Blais, B. C. Sanders, A. L. Van, A. Fedorov, A. Wallraff |

Evolutionary algorithms for hard quantum control University of Calgary | Publication | 2014-01-01 | E. Zahedinejad, S. Schirmer, B. C. Sanders |

Nonzero classical discord University of Calgary | Publication | 2015-01-01 | V. Gheorghiu, M. C. De, B. C. Sanders |

Probing multipartite entanglement in a coupled Jaynes-Cummings system University of Calgary | Publication | 2012-01-01 | P. Xue, Z. Ficek, B. C. Sanders |

Coherent control of low loss surface polaritons University of Calgary | Publication | 2008-01-01 | A. Kamli, S. Moiseev, B. C. Sanders |

Fast All-Optical SwitchPublication Date: September 11, 2012.
Click to download University of Calgary | Product | 2010-05-12 | S. Moiseev, A. Kamli, B. C. Sanders |

Quantum computation with coherent spin states and the close Hadamard problem University of Calgary | Publication | 2016-01-01 | M. Adock, P. Høyer, B. C. Sanders |

Controlling adaptivequantum phase estimation with scalable reinforcement learning University of Calgary | Publication | 2016-04-01 | P. Palittapongarnpim, P. Wittek, B. C. Sanders |

Single-shot Adaptive Measurement for Quantum-enhanced Metrology University of Calgary | Publication | 2016-08-01 | P. Pallitapongarnpim, P. Wittek, B. C. Sanders |

State-independent preparation uncertainty relations University of Calgary | Publication | 2014-01-01 | H. G. De, L. Maccone, B. C. Sanders, N. Shukla |

Designing high-fidelity single-shot three-qubit gates: A machine-learning approach University of Calgary | Publication | 2016-01-01 | E. Zahedinejad, J. Ghosh, B. C. Sanders |

Performance of PML absorbing boundary conditions in 3D photonic crystal waveguides University of Calgary | Publication | 2003-01-01 | A. R. Weily, L. Horvath, K. P. Esselle, B. C. Sanders |

Security aspects of practical quantum cryptography University of Calgary | Publication | 2000-01-01 | G. Brassard, N. Lutkenhaus, T. Mor, B. C. Sanders |

Radiating dipoles in photonic crystals University of Calgary | Publication | 2000-09-01 | K. Busch, N. Vats, S. John, B. C. Sanders |

Quantum walks in higher dimensions University of Calgary | Publication | 2002-03-01 | T. D. Mackay, S. D. Bartlett, L. T. Stephenson, B. C. Sanders |

A planar resonator antenna based on a woodpile EBG material University of Calgary | Publication | 2005-01-01 | A. R. Weily, L. Horvath, K. P. Esselle, B. C. Sanders, T. S. Bird |

Post-processing with linear optics for improving the quality of single-photon sources University of Calgary | Publication | 2004-01-01 | D. W. Berry, S. Scheel, C. R. Myers, B. C. Sanders, P. L. Knight, R. Laflamme |

Tripartite Quantum State Sharing University of Calgary | Publication | 2004-04-01 | A. M. Lance, T. Symul, W. P. Bowen, B. C. Sanders, P. K. Lam |

Efficient Quantum Algorithms for Simulating Sparse Hamiltonians University of Calgary | Publication | 2006-12-01 | D. W. Berry, G. Ahokas, R. Cleve, B. C. Sanders |

Experimental woodpile EBG waveguides, bends and power dividers at microwave frequencies University of Calgary | Publication | 2006-01-01 | A. R. Weily, K. P. Esselle, T. S. Bird, B. C. Sanders |

Dual resonator 1-D EBG antenna with slot array feed for improved radiation bandwidth University of Calgary | Publication | 2007-01-01 | A. R. Weily, K. P. Esselle, T. S. Bird, B. C. Sanders |

Gaussian quantum marginal problem University of Calgary | Publication | 2008-01-01 | J. Eisert, T. Tyc, T. Rudolph, B. C. Sanders |

Super- and subradiant emission of two-level systems in the near-Dicke limit University of Calgary | Publication | 2008-01-01 | P. Brooke, K. -. Marzlin, J. Cresser, B. C. Sanders |

Uniform cross-phase modulation for nonclassical radiation pulses University of Calgary | Publication | 2010-01-01 | K. -. Marzlin, Z. -. Wang, S. Moiseev, B. C. Sanders |

Entanglement creation with negative index metamaterials University of Calgary | Publication | 2012-01-01 | M. Siomau, A. Kamli, S. Moiseev, B. C. Sanders |

Differential evolution for many-particle adaptive quantum metrology University of Calgary | Publication | 2013-01-01 | N. Lovett, C. Crosnier, M. Perarnau-Llobet, B. C. Sanders |

Quantum Frameness for C P T Symmetry University of Calgary | Publication | 2013-07-01 | M. Skotiniotis, B. Toloui, I. T. Durham, B. C. Sanders |

Photon-mediated interactions between distant artificial atoms University of Calgary | Publication | 2013-01-01 | A. V. Loo, A. Fedorov, K. Lalumière, B. C. Sanders, A. Blais, A. Wallraff |

Observation of quasiperiodic dynamics in a one-dimensional quantum walk of single photons in space University of Calgary | Publication | 2014-01-01 | P. Xue, L. Qian, B. Tang, B. C. Sanders |

Nonlinear phase shifts of light trapped in a two-component Bose-Einstein condensate University of Calgary | Publication | 2014-01-01 | C. Trail, K. Almutairi, D. Feder, B. C. Sanders |

Coincidence landscapes for three-channel linear optical networks University of Calgary | Publication | 2014-01-01 | H. Guise, S. -. Tan, I. Poulin, B. C. Sanders |

Quantum frameness for CPT inversion symmetry University of Calgary | Publication | 2013-01-01 | M. Skotiniotis, B. Toloui Semnani, I. T. Durham, B. C. Sanders |

Correction: Surface residues dynamically organize water bridges to enhance electron transfer between proteins (PNAS, vol 107, pg 11799, 2010) University of Calgary | Publication | 2013-01-01 | A. d. Lande, N. Babcock, J. Řezáč, B. C. Sanders, D. Salahub |

Entangling identical bosons in optical tweezers via exchange interaction University of Calgary | Publication | 2008-05-01 | N. Babcock, R. Stock, M. G. Raizen, B. C. Sanders |

Low-cost 1-D EBG resonator antenna with high directivity University of Calgary | Publication | 2004-01-01 | A. R. Weily, K. P. Esselle, L. Horvath, B. C. Sanders, T. S. Bird |

Experimental demonstration of (2,3) threshold quantum state sharing University of Calgary | Publication | 2003-01-01 | A. M. Lance, T. Symul, W. P. Bowen, B. C. Sanders, P. K. Lam |

Entanglement, or quantum inseparability, is a profound property of nature that enables information to be stored, communicated and processed in a decidedly non-classical fashion University of Calgary | Publication | 2003-01-01 | H. d. Guise, A. C. Funk, M. G. Raymer, B. C. Sanders |

Dynamical entanglement in chaotic systems University of Calgary | Presentation | 2004-06-14 | S. Ghose, G. X. Wang, H. I. Deutsch, B. C. Sanders |

Experimental demonstration of (2,3) threshold quantum state sharing University of Calgary | Presentation | 2003-12-01 | M. A. Lance, T. Symul, P. W. Bowen, B. C. Sanders, K. P. Lam |

Entangling neutral atoms with symmetrization-dependent dynamicsTrapped neutral atoms provide a promising medium in which to perform quantum computations since they have long decoherence times and can easily be interfaced with light for single-qubit operations and measurements. Despite these advantages, reliable methods for entangling and transporting atomic qubits must be devised before practical atomic quantum information processing devices can be realized. We propose a method for entangling a pair of indistinguishable neutral atoms stored in separated optical dipole traps. We model this trapping potential in one dimension as a pair of Gaussian wells that can be brought together for atoms to interact. The dynamics of this process depend on the symmetrization parameters of the initial state, and by choosing the correct interaction time a controlled-phase gate can be designed. Adiabatic separation guarantees that the atoms end up in opposite traps. We provide both adiabatic and time-dependent numerical simulations of the entangling process. Additionally, we consider a novel method for creating entangled qubits via selective excitation of atoms in such optical dipole traps. University of Calgary | Presentation | 2007-06-07 | N. Babcock, R. Stock, G. M. Raizen, B. C. Sanders |

A contextual toy model University of Calgary | Presentation | 2008-08-21 | M. Skotiniotis, G. Gour, A. Roy, B. C. Sanders |

Cooperative emission into surface plasmons University of Calgary | Presentation | 2008-08-21 | J. Choquette, K. Marzlin, R. Stock, B. C. Sanders |

Giant cross-phase modulation in double electromagnetically induced transparency and its applications University of Calgary | Presentation | 2008-08-23 | Z. Wang, K. Marzlin, S. Moiseev, B. C. Sanders |

Bioelectric motors: bridging the gapA series of membrane-bound proteins called the cellular respiratory chain (or "electron transport chain") serves as the power system sustaining all known oxygen-breathing life on Earth. This system is essentially a chain of electric motors, powered by the flow of tunneling electrons. Thanks to the advent of sophisticated experimental and numerical techniques, biological molecules have become a particularly attractive medium in which to study quantum transport.
The bacterium Paracoccus denitrificans is believed to share a common ancestor with the modern mitochondrion (the "powerhouse of the cell"). I present numerical characterizations of molecular motion at an inter-protein electron transfer interface in the respiratory chain of Paracoccus denitrificans. I am motivated by a recent experiment in which anomalous electron transfer rates were measured for this tunneling step [Ma et al., Biochemistry 46, 11137 (2007)]. I argue that specific amino acids are likely to harness nearby water molecules to bridge the inter-protein gap, enhancing the tunneling rate. University of Calgary | Presentation | 2009-03-25 | N. Babcock, A. l. De, D. Salahub, B. C. Sanders |

Analytical results for coherent state quantum process tomographyA general method of characterizing quantum optical process was introduced in [1], based on probing with coherent states and approximating the P-function with a regular function. In the present work, by considering the fact that in a realistic experiment we are dealing with a finite dimensional Hilbert space, the approximation for P-function can be avoided. We extend the technique to the multimode case and to conditional processes. Furthermore, based on the effect of some of the fundamental quantum optical processes on the coherent states, we analytically derive their superoperator in the Fock basis.
University of Calgary | Presentation | 2009-08-21 | S. Rahimi-Keshari, A. Mann, A. Scherer, B. C. Sanders |

Entanglement Sharing SchemeEntanglement is a necessary resource for quantum information tasks such as teleportation, dense coding, and Ekert QKD scheme. In entanglement sharing scheme, one share of a bipartite entangled pair is encoded and distributed to untrusted players in a way that they must collaborate in groups to unlock the entanglement. I show how to use quantum error correcting codes to share maximally entangled states between a dealer and collaborating groups of players by exploiting quantum secret sharing concepts and techniques.
University of Calgary | Presentation | 2012-02-09 | H. R. Choi, B. Fortescue, G. Gour, B. C. Sanders |

Communication of information in the absence of a shared frame of referenceIn a communication protocol the sender, Alice, encodes classical messages by preparing a quantum system in a particular state and sending it to the receiver, Bob, who decodes the message by an appropriate quantum measurement. Implicit in the protocol is the assumption that whatever the physical encoding employed by Alice, whether it is the spin of particle, or the energy levels of an atom, is known to Bob. This assumption amounts to Alice and Bob sharing a common reference frame relative to which the states of physical systems are described. The lack of a shared frame of reference imposes severe restrictions on many communication and computational tasks. We obtain the optimal protocols for two cases: where invariant subspaces are available and where they are not.
University of Calgary | Presentation | 2011-03-09 | M. Skotiniotis, A. Roy, G. Gour, B. C. Sanders |

QED of surface plasmonsA full quantum description of photons and surface plasmons near an interface between lossy dielectrics is given, allowing estimation of SP-induced noise. The emitted radiation of a decaying atom near the interface is characterized. University of Calgary | Presentation | 2007-06-14 | J. Choquette, K. Marzlin, R. Stock, B. C. Sanders |

Computing time ordered operator exponentials efficiently and accurately University of Calgary | Presentation | 2008-11-17 | N. Wiebe, W. D. Berry, P. Høyer, B. C. Sanders |

Electromagnetically induced transparency combined with lasing without inversion in superconducting circuitsBy strongly driving a transition of a three-level atom one dresses the atomic states with the external field resulting in an Autler-Townes energy level splitting. The absorption and dispersion properties of the medium can then be controlled optically in order to realize effects such as electromagnetically-induced transparency (EIT) and lasing without inversion (LWI). In atomic systems, these two effects are however usually not realized together. Away from their symmetry point, both the flux qubit and the fluxonium form a $\Delta$-configuration where transitions between any two of the lowest three states are allowed. When driven by two resonant fields, we show that the system exhibits a transparency frequency window sandwiched between an absorption band (EIT) on one side and an amplification band (LWI) on the other. Finally, we discuss a possible implementation and measurement scheme using the flux qubit or the fluxonium charge qubit. University of Calgary | Presentation | 2010-03-19 | J. Bourassa, J. Joo, A. Blais, B. C. Sanders |

Threshold quantum secret sharing using graph states of prime-dimensional systemsSecret sharing schemes allow a classical or quantum secret to be divided among many parties such that it can be recovered only by some specified set of parties collaborating in order to do so. It is known that arbitrary secret sharing schemes may be constructed by concatenating threshold schemes, in which the secret can be recovered by any sufficiently large number of parties, and the remainder are denied any knowledge of the secret
I will discuss a formalism within which, using entangled graph states of prime-dimensional systems, a variety of different threshold secret sharing schemes (involving both quantum and classical secrets and quantum and classical channels shared between parties) may be unified. I will give explicit protocols for three varieties of secret sharing within this formalism, including some for which the analogous formalism using graph states of two-dimensional systems is not sufficient. University of Calgary | Presentation | 2010-07-19 | B. Fortescue, A. Keet, D. Markham, B. C. Sanders |

Entanglement-enhanced classical communication without a shared frame of referenceTwo parties, Alice and Bob, share a communication channel but lack a shared reference frame.
Alice's task is to communicate a message to Bob, and she does so by preparing an object in a state
that represents the message, for example as a rotation, and transmitting this object to Bob who
measures the state of the object to reveal the message. Due to the lack of a shared reference frame,
Bob may not be able to perform the appropriate measurement to learn the message. For example
Bob may be lacking the reference angle against which to measure the rotation. Here we tackle the
problem of how two parties, lacking a shared reference frame, could prepare and measure a message
in order to communicate successfully. We deem a prepare-and-measure procedure to be successful
if it minimizes the average error over all received messages.
In our communication protocol the parties circumvent the lack of a shared reference frame by
preparing and sending two objects such that the message is the relative transformation parameter
from the state of the rst object into the state of the second object. Bob performs joint measurements
on the pair of received objects to infer the message from the measurement outcomes. Our aim is
to devise a prepare-and-measure scheme that ensures the highest average success rate for sending
messages as relative transformation parameters between two objects.
We use Schur's lemmas, group representation theory, and quantum estimation theory to derive
optimal measurements given constraints imposed on Alice's preparations. We can nd closed-form
solutions for prepare-and-measure schemes for some constraints and employ numerical methods to
obtain optimal protocols in the more general cases. In particular we discover that, whereas preparing
objects in an entangled state is sucient for success, entanglement is not always necessary. Our
theory lays the groundwork for circumventing a lack of reference frames between parties by sending
messages through the parameter of a relative transformation between two objects. University of Calgary | Presentation | 2010-08-26 | M. Skotiniotis, A. Roy, G. Gour, B. C. Sanders |

Secret sharing with higher-dimensional graph states University of Calgary | Presentation | 2010-08-26 | B. Fortescue, A. Keet, D. Markham, B. C. Sanders |

A molecular breakwater enhances electron transfer between proteinsDoes natural selection optimize molecular biomachinery at the quantum level? We present statistical characterizations of molecular dynamics at an interprotein electron transfer (ET) interface. In simulations of the wild-type protein complex, we find that the most frequently occurring molecular configurations afford superior electronic coupling due to the consistent presence of a single water molecule hydrogen-bonded between the donor and acceptor sites. We attribute the persistence of this water bridge to a ``molecular breakwater'' composed of several hydrophobic residues surrounding the acceptor site. The breakwater supports the function of solvent-organizing residues by limiting the exchange of water molecules between the sterically constrained ET region and the surrounding bulk. When the breakwater is affected by a mutation, bulk solvent molecules disrupt the water bridge, resulting in reduced electronic coupling. These results suggest that protein surface residues may stabilize interprotein solvent dynamics to enable coherent ET along a single molecular pathway. University of Calgary | Presentation | 2011-03-23 | N. Babcock, A. l. De, J. Řezáč, B. C. Sanders, D. Salahub |

Optical self-phase modulation via nonlinear spin-wave dynamics in a BECLight can be stored in Bose-Einstein condensates for more than one second using quantum memory techniques based on electromagnetically induced transparency [1]. In recent theoretical work [2], Rispe et al. proposed a method for storing photons in Bose-Einstein condensates to create a photon-photon gate. This gate uses the collisions between atoms in order to generate a phase shift that is dependent on the presence or absence of photons. We go beyond the single photon case considered in the previous scheme [2] to the many-photon case in the mean-field treatment and under the Thomas-Fermi approximation, where this scheme leads to strong phase self-modulation. That medium will allow superposition of an arbitrary number of photons to undergoing nonlinear evolution and in particular produce "cat states" [3]. We generate "cat states" [3] from coherent states through the collision-induced interaction.
References: [1] R. Zhang, S. R. Garner, and L.V. Hau, Phys. Rev. Lett. 103, 233602 (2009). [2] A. Rispe, B. He, and C. Simon ,Phys. Rev. Lett. 107, 043601 (2011). [3] B. Yurke, and D. Stoler, Phys. Rev. Lett. 57, 13 (1986). University of Calgary | Presentation | 2012-07-27 | K. Almutairi, C. Trail, C. Simon, B. C. Sanders |

Entanglement dynamics in a chaotic systemWe analyze quantum signatures of chaos in the entanglement dynamics of cold atoms trapped in a magneto-optical lattice. The system has two coupled degrees of freedom (atomic position and spin), allowing the dynamics of entanglement to be studied both theoretically and experimentally. The entanglement between spin and motional degrees of freedom exhibits quasi-periodic behavior for states localized in a regular region of phase space. For states localized in a chaotic region, the growth of entanglement is faster and no quasi-periodic behavior is evident. We explain the main features of the entanglement dynamics by examining the support of the initial state on the system eigenstates. Our analysis is general and applicable to other quantum chaotic systems with unitary evolution.
University of Calgary | Presentation | 2004-07-22 | S. Ghose, X. -. Wang, H. I. Deutsch, B. C. Sanders |

Nonlinear dynamics of atomic Bose-Einstein condensates University of Calgary | Presentation | 1997-01-03 | S. Dyrting, J. G. Milburn, P. W. Zhang, B. C. Sanders |

Coherent & incoherent electron transfer in biological systemsIntermolecular electron transport is vital to the life of all respiring organisms (i.e., the vast majority of Earth's biomass). During electron transfer, any structures between the donor and acceptor molecules are collectively referred to as the "bridge." Interferences between multiple tunneling pathways through the bridge can enhance or reduce electronic coupling. A clear picture of decoherence due to dynamic bridge effects is therefore necessary to understand electron transport in biological systems. In respiring organisms, adenosine-5'-triphosphate (ATP) is recycled at a membrane-bound complex called the "electron transport chain," which in turn is powered by electricity produced from the oxidation of food (chemosynthesis) or the absorption of sunlight (photosynthesis). In this work, we examine a single bridging step in the electron transport chain of Paracoccus denitrificans. Recent experiments have shown this process to be extremely sensitive to the change of just a few atoms in the surrounding protein structure. We hypothesize that this reaction is mediated by a bridge of water molecules stabilized by nearby amino acid residues, effectively suppressing the decoherence of the through-water coupling term. We test this hypothesis using molecular mechanics and density functional theory to calculate the electronic coupling matrix elements for a variety of configurations. We believe the mathematical tools and intuition of quantum information theory will help provide deeper insight into the role of decoherence in this intriguing phenomenon. University of Calgary | Presentation | 2008-06-17 | N. Babcock, A. l. De, D. Salahub, B. C. Sanders |

Simulating quantum dynamics on a quantum computerWe develop an efficient quantum algorithm for simulating time-dependent Hamiltonian evolution of general input states on a quantum computer. Given conditions on the smoothness of the Hamiltonian, the complexity of the algorithm is close to linear in the evolution time, and therefore is comparable to algorithms for time-independent Hamiltonians. In addition, we show how the complexity can be reduced by optimizing the time steps. The complexity of the algorithm is quantified by calls to an oracle, which yields information about the Hamiltonian, and accounts for all computational resources. In contrast to previous work, which allowed an oracle query to yield an arbitrary number of bits or qubits, we assign a cost for each bit or qubit accessed. This per-bit or per-qubit costing of oracle calls reveals hitherto unnoticed simulation costs. We also account for discretization errors in the time and the representation of the Hamiltonian. We generalize the requirement of sparse Hamiltonians to being a sum of sparse Hamiltonians in various bases for which the transformation to a sparse Hamiltonian may be performed efficiently. University of Calgary | Presentation | 2011-03-24 | N. Wiebe, W. D. Berry, P. Høyer, B. C. Sanders |

Cooperative effects for qubits in a transmission line: experiment University of Calgary | Presentation | 2012-03-02 | F. L. Van, A. Fedorov, K. Lalumière, B. C. Sanders, A. Blais, A. Wallraff |

Entanglement sharing schemes via quantum error-correcting codes University of Calgary | Presentation | 2011-06-17 | H. R. Choi, B. Fortescue, G. Gour, B. C. Sanders |

Entanglement sharing protocolsEntanglement sharing schemes are important as a tool for secure quantum communication in a
network where some subsets of players are authorized to access the transmitted quantum information and other subsets must be denied any quantum information. We conjecture that every stabilizer error correcting code is an entanglement sharing scheme. We test this conjecture with known codes including Shor's 9-qubit code, Steane's 7-qubit code and the 5-qubit code. If our conjecture is true, then we can use existing stabilizer error correcting codes as candidates for entanglement sharing rather than having to construct entanglement sharing schemes ab initio. University of Calgary | Presentation | 2011-11-04 | H. R. Choi, B. Fortescue, G. Gour, B. C. Sanders |

Stabilizer formalism for generalized concatenated quantum codes University of Calgary | Publication | 2013-07-01 | Y. J. Wang, B. Zeng, M. Grassl, B. C. Sanders |

A molecular breakwater enhances electron transfer between proteins University of Calgary | Publication | 2011-03-01 | N. Babcock, A. l. De, J. Rezác, B. C. Sanders, D. Salahub |

Cooperative effects for qubits in a transmission line: experiment University of Calgary | Publication | 2012-03-01 | A. L. Van, A. Fedorov, K. Lalumière, B. C. Sanders, A. Blais, A. Wallraff |

Erratum: Coincidence landscapes for three-channel linear optical networks [Phys. Rev. A 89, 063819 (2014)] University of Calgary | Publication | 2014-01-01 | H. G. De, S. -. Tan, I. Poulin, B. C. Sanders |

Immanants for three-channel linear optical networks University of Calgary | Publication | 2014-01-01 | H. d. Guise, S. -. Tan, I. Poulin, B. C. Sanders |

Quantum frameness for charge-parity-time inversion symmetry University of Calgary | Publication | 2013-01-01 | M. Skotiniotis, B. Toloui Semnani, I. Durham, B. C. Sanders |

EBG Materials and Antennas University of Calgary | Publication | 2009-01-01 | A. Weily, T. Bird, K. Esselle, B. C. Sanders |

Realization of the contextuality-nonlocality tradeoff with a qubit-qutrit photon pairWe report our experimental results on the no-disturbance principle, which imposes a fundamental monogamy relation on contextuality versus nonlocality. We employ a photonic qutrit-qubit hybrid to explore no-disturbance monogamy at the quantum boundary spanned by noncontextuality and locality inequalities. In particular, we realize the single point where the quantum boundary meets the no-disturbance boundary. Our results agree with quantum theory and satisfy the stringent monogamy relation thereby providing direct experimental evidence of a tradeoff between locally contextual correlations and spatially separated correlations. Thus, our experiment provides evidence that entanglement is a particular manifestation of a more fundamental quantum resource.
University of Calgary | Publication | 2016-01-01 | X. Zhan, X. Zhang, J. Li, B. C. Sanders, P. Xue |

Accurate and precise characterization of linear optical interferometersWe combine single- and two-photon interference procedures for characterizing any multi-port linear optical interferometer accurately and precisely. Accuracy is achieved by estimating and correcting systematic errors that arise due to spatiotemporal and polarization mode mismatch. Enhanced accuracy and precision are attained by fitting experimental coincidence data to curve simulated using measured source spectra. We employ bootstrapping statistics to quantify the resultant degree of precision. A scattershot approach is devised to effect a reduction in the experimental time required to characterize the interferometer. The efficacy of our characterization procedure is verified by numerical simulations. University of Calgary | Publication | 2016-01-01 | I. Dhand, A. Khalid, H. Lu, B. C. Sanders |

Generalized multi-photon quantum interferenceNon-classical interference of photons lies at the heart of optical quantum information processing. This effect is exploited in universal quantum gates as well as in purpose-built quantum computers that solve the BosonSampling problem. Although non-classical interference is often associated with perfectly indistinguishable photons this only represents the degenerate case, hard to achieve under realistic experimental conditions. Here we exploit tunable distinguishability to reveal the full spectrum of multi-photon non-classical interference. This we investigate in theory and experiment by controlling the delay times of three photons injected into an integrated interferometric network. We derive the entire coincidence landscape and identify transition matrix immanants as ideally suited functions to describe the generalized case of input photons with arbitrary distinguishability. We introduce a compact description by utilizing a natural basis which decouples the input state from the interferometric network, thereby providing a useful tool for even larger photon numbers. University of Calgary | Publication | 2015-01-01 | M. Tillmann, S. -. Tan, S. E. Stoeckl, B. C. Sanders, H. d. Guise, R. Heilmann, S. Nolte, A. Szameit, P. Walther |

Propagation of radiation pulses through gas-plasma mixtures University of Calgary | Publication | 2016-01-01 | K. -. Marzlin, A. Panwar, M. S. Razul, B. C. Sanders |

Spacetime replication of continuous variable quantum information University of Calgary | Publication | 2016-01-01 | P. Hayden, S. Nezami, G. Salton, B. C. Sanders |

Decomposition of split-step quantum walks for simulating Majorana modes and edge states University of Calgary | Publication | 2017-01-01 | W. Zhang, S. Goyal, C. Simon, B. C. Sanders |

Creating cat states in one-dimensional quantum walks using delocalized initial states University of Calgary | Publication | 2016-01-01 | W. -. Zhang, S. K. Goyal, F. Gao, B. C. Sanders |

Continuous variable (2, 3) threshold quantum secret sharing schemes University of Calgary | Publication | 2003-01-01 | A. M. Lance, T. Symul, W. P. Bowen, T. Tyc, B. C. Sanders, P. K. Lam |

Effects of temperature and ground-state coherence decay on enhancement and amplification in a Δ atomic system University of Calgary | Publication | 2014-01-01 | M. Manjappa, S. Undurti, A. Karigowda, A. Narayanan, B. C. Sanders |

Discrete time quantum walk with nitrogen-vacancy centers in diamond coupled to a superconducting flux qubit University of Calgary | Publication | 2013-01-01 | A. Hardal, P. Xue, Y. Shikano, O. Mustecaplioglu, B. C. Sanders |

Is quantum secret sharing different than the sharing of a quantum secret? University of Calgary | Publication | 2004-01-01 | A. M. Lance, T. Symul, W. P. Bowen, T. Tyc, B. C. Sanders, P. K. Lam |

Continuous variable quantum teleportation and quantum secret sharing University of Calgary | Presentation | 2003-12-01 | K. P. Lam, P. W. Bowen, T. Symul, M. A. Lance, B. C. Sanders, T. Tyc, C. T. Ralph |

Rapid control and measurement of clock-state qubits in Yb and Sr for quantum information processing University of Calgary | Presentation | 2006-07-17 | R. Stock, N. Babcock, M. A. Dudarev, G. M. Raizen, B. C. Sanders |

Giant optical nonlinearities between two matched pulsesOne of the primary limitations of nonlinear optics is that relatively high intensities are needed to produce a noticeable effect. However, in an atomic system with electromagnetically induced transparency (EIT) it is possible to observe nonlinearities at light levels as low as a few photons per atomic cross section [1]. Implementation of the EIT-based nonlinearity with pulsed light may however be challenging as it requires the interacting pulses to propagate at equal group velocities. Recently, a scheme satisfying this requirement was proposed which employs double EIT in atomic Rubidium-87 [2]. We report on our recent progress towards experimentally realizing this scheme. We have successfully demonstrated a double EIT system in which two separate pulses may be simultaneously slowed or stored. By applying a large, homogenous magnetic field across the atomic vapor, thus splitting the atomic levels, we create a large nonlinear interaction in the form of XPM. *References: [1]: H. Schmidt, and V. Imamoglu, Optics Letters 21 23 1996 [2]: Z.B. Wang, K.P. Marzlin, B.C. Sanders, Phys. Rev. Lett. 97 06, 2006 University of Calgary | Presentation | 2008-05-30 | A. MacRae, G. Campbell, Z. Wang, K. Marzlin, B. C. Sanders, A. Lvovsky |

Graph states and ramp schemes for quantum secret sharingI will discuss our recent work in developing new protocols for quantum secret sharing (QSS), a cryptographic scheme in which an encoded quantum "secret" is divided between several "players" such that only certain subsets of players may recover it. We have found a class of protocols based on graph states which allow for efficient (i.e. player states of the same dimension as the secret) QSS for states of prime dimension. We have also found examples of "ramp" schemes for QSS, in which the efficiency can be improved by sacrificing some security. I will discuss these and the use of shared entanglement as a measure of the players' information about the secret.
University of Calgary | Presentation | 2011-02-24 | B. Fortescue, A. Keet, D. Markham, G. Gour, B. C. Sanders |

A continuous-variable approach to process tomographyWe propose and demonstrate experimentally a technique for estimating quantum-optical processes in the continuous-variable domain. The process data is determined by applying the process to a set of coherent states and measuring the output. The process output for an arbitrary input state can then be obtained from its Glauber-Sudarshan expansion. Although such expansion is generally singular, it can be arbitrarily well approximated with a regular function. University of Calgary | Presentation | 2008-08-26 | M. Lobino, E. Figueroa, D. Korystov, C. Kupchak, B. C. Sanders, A. Lvovsky |

New directions in quantum secret sharing University of Calgary | Presentation | 2010-11-19 | B. Fortescue, A. Keet, D. Markham, G. Gour, B. C. Sanders |

Stability theorem of depolarizing channels for the minimal output quantum Rényi entropiesWe show that the stability theorem of the depolarizing channel holds for the output quantum p-R\'enyi entropy for p≥2 or p=1, which is an extension of the well known case p=2. As an application, we present a protocol in which Bob determines whether Alice prepares a pure quantum state close to a product state. In the protocol, Alice transmits to Bob multiple copies of a pure state through a depolarizing channel, and Bob estimates its output quantum p-R\'enyi entropy. By using our stability theorem, we show that Bob can determine whether her preparation is appropriate. University of Calgary, University of Alberta | Publication | 2016-01-01 | E. Bae, G. Gour, S. Lee, J. Park, B. C. Sanders |

Uncover topology by quantum quench dynamics University of Calgary | Publication | 2018-01-01 | W. Sun, C. Yi, B. Wang, W. Zhang, B. C. Sanders, X. Xu, Z. Wang, J. Schmiedmayer, Y. Deng, X. Liu, S. Chen, J. Pan |

Demonstration of a high-contrast optical switching an atomic Delta system University of Calgary | Publication | 2017-01-01 | M. Ghosh, A. Karigowda, A. Jayaraman, F. Bretenaker, B. C. Sanders, A. Narayanan |

Classical and quantum fingerprinting with shared randomness and one-sided error University of Calgary | Publication | 2005-05-01 | R. T. Horn, A. Scott, J. Walgate, R. Cleve, A. Lvovsky, B. C. Sanders |

Realization of single-qubit positive operator-valued measurement via a one-dimensional photonic quantum walkWe perform generalized measurements of a qubit by realizing the qubit as a coin in a photonic quantum walk and subjecting the walker to projective measurements. Our experimental technique can be used to realize photonically any rank-1 single-qubit positive operator-valued measure via constructing an appropriate interferometric quantum-walk network and then projectively measuring the walker's position at the final step.
University of Calgary | Publication | 2015-01-01 | Z. Bian, J. Li, H. Qin, X. Zhan, R. Zhang, B. C. Sanders, P. Xue |

Quantum process tomography with coherent states, New Journal of Physics University of Calgary | Publication | 2011-01-01 | S. Rahimi-Keshari, A. Scherer, A. Mann, A. Rezakhani, A. Lvovsky, B. C. Sanders |

Localized state in a two-dimensional quantum walk on a disordered latticeWe realize a pair of simultaneous ten-step one-dimensional quantum walks with two walkers sharing coins, which we prove is analogous to the ten-step two-dimensional quantum walk with a single walker holding a four-dimensional coin. Our experiment demonstrates a ten-step quantum walk over an 11x11 two-dimensional lattice with a line defect, thereby realizing a localized walker state. University of Calgary | Publication | 2015-01-01 | P. Xue, R. Zhang, Z. Bian, X. Zhan, H. Qin, B. C. Sanders |

Detecting topological invariants in nonunitary discrete-time quantum walks University of Calgary | Publication | 2014-01-01 | X. Zhan, L. Xiao, Z. Bian, K. Wang, X. Qiu, B. C. Sanders, W. Yi, P. Xue |

Entanglement-enhanced quantum metrology in a noisy environment University of Calgary | Publication | 2018-01-01 | K. Wang, X. Wang, X. Zhan, Z. Bian, J. Li, B. C. Sanders, P. Xue |

Strong coherent light amplification with double electromagnetically induced transparency coherences University of Calgary | Publication | 2017-01-01 | D. Wang, C. Liu, C. Xiao, J. Zhang, H. M. Alotaibi, B. C. Sanders, L. Wang, S. Zhu |

Characterizing the rate and coherence of single-electron tunneling between two dangling bonds on the surface of silicon University of Calgary, University of Alberta | Publication | 2014-01-01 | Z. Shaterzadeh-Yazdi, L. Livadaru, M. Taucer, J. Mutus, J. Pitters, R. A. Wolkow, B. C. Sanders |

Experimental quantum-walk revival with a time-dependent coin University of Calgary | Publication | 2015-01-01 | P. Xue, R. Z. R, H. Qin, X. Zhan, Z. -. Bian, J. Li, B. C. Sanders |

Dangling-bond charge qubit University of Calgary, University of Alberta | Presentation | 2010-05-03 | L. Livadaru, P. Xue, Z. Shaterzadeh-Yazdi, A. G. DiLabio, J. Mutus, L. J. Pitters, B. C. Sanders, R. A. Wolkow |

Continuous Variable Quantum Teleportation and Quantum Secret Sharing University of Calgary | Publication | 2003-01-01 | P. K. Lam, W. P. Bowen, N. Treps, B. C. Buchler, R. Schnabel, T. Symul, A. M. Lance, B. C. Sanders, T. Tyc, T. C. Ralph |

Quantum-optical process tomography using coherent states University of Calgary | Presentation | 2010-07-19 | M. Lobino, D. Korystov, C. Kupchak, E. Figueroa, R. Kumar, E. Barrios, S. Rahimi-Keshari, A. Scherer, B. C. Sanders, A. Lvovsky |

Experimental blind quantum computing for a classical client University of Calgary | Publication | 2017-01-01 | H. Huang, Q. Zhao, X. Ma, C. Liu, Z. Su, X. Wang, L. Li, N. Liu, B. C. Sanders, C. Lu, J. Pan |

Journeys from quantum optics to quantum technology University of Calgary | Publication | 2017-01-01 | S. Barnett, A. Beige, A. Ekert, B. Garraway, C. Keitel, V. Kendon, M. Lein, G. Milburn, H. Moya-Cessa, M. Murao, J. Pachos, G. Palma, E. Paspalakis, S. Phoenix, B. Piraux, M. Plenio, B. C. Sanders, J. Twamley, A. Vidiella-Barranco, M. Kim |