A simple necessary decoherence condition for a set of histories University of Calgary | Publication | 2004-06-01 | A. Scherer, A. N. Soklakov, R. Schack |
Initial states and decoherence of histories University of Calgary | Publication | 2005-01-01 | A. Scherer, A. N. Soklakov |
Classical predictability and coarse-grained evolution of the quantum baker’s map University of Calgary | Publication | 2006-06-01 | A. Scherer, A. N. Soklakov, R. Schack |
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 |
Quantum states after N concatenated entanglement swappings under real-world conditions University of Calgary | Presentation | 2009-05-25 | A. Scherer, B. C. Sanders |
Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium University of Calgary | Publication | 2006-03-01 | T. Konrad, A. Scherer, M. Nock, J. Audretsch |
Announcing single photons from imperfect sources by means of “interaction-free” measurements University of Calgary | Publication | 2008-06-01 | T. Konrad, A. Scherer, M. Nock, J. Audretsch |
Continuous-mode effects and photon-photon phase gate performance University of Calgary | Publication | 2012-03-01 | B. He, A. Scherer |
Quantum process tomography with coherent states University of Calgary | Publication | 2011-01-01 | S. Rahimi-Keshari, A. Scherer, A. Mann, A. Rezakhani, A. Lvovsky |
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 |
Sequence of unsharp measurements enabling a real-time visualization of a quantum oscillation University of Calgary | Publication | 2001-04-01 | J. Audretsch, T. Konrad, A. Scherer |
Quantum-optical weak measurements can visualize photon dynamics in real time University of Calgary | Publication | 2002-02-01 | J. Audretsch, T. Konrad, A. Scherer |
Coupled Ito equations of continuous quantum state measurement and estimation University of Calgary | Publication | 2006-09-01 | L. Diósi, T. Konrad, A. Scherer, J. Audretsch |
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 |
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 |