Transition to classical chaos in a coupled quantum system through continuous measurement University of Calgary | Publication | 2004-05-01 | S. Ghose, P. Alsing, I. Deutsch, T. Bhattacharya, S. Habib |

Atomic motion in magneto-optical double-well potentials: A testing ground for quantum chaos University of Calgary | Publication | 2001-10-01 | S. Ghose, P. M. Alsing, I. H. Deutsch |

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 |

Tripartite Entanglement versus Tripartite Nonlocality in Three-Qubit Greenberger-Horne-Zeilinger-Class States University of Calgary | Publication | 2009-06-01 | S. Ghose, N. Sinclair, S. Debnath, P. Rungta, R. Stock |

Multiqubit nonlocality in families of 3- and 4-qubit entangled states University of Calgary | Publication | 2010-10-01 | S. Ghose, S. Debnath, N. Sinclair, A. Kabra, R. Stock |

The transition to classical chaos in a coupled quantum system through continuous measurement University of Calgary | Publication | 2004-05-01 | S. Ghose, P. M. Alsing, T. Bhattacharya, S. Habib, K. Jacobs |

Recovering classical dynamics from coupled quantum systems through continuous measurement University of Calgary | Publication | 2003-05-01 | S. Ghose, P. M. Alsing, I. H. Deutsch, T. Bhattacharya, S. Habib, K. Jacobs |

Analysis of a tripartite Bell inequality for 3-qubit states University of Calgary | Publication | 2009-01-01 | S. Ghose, N. Sinclair, S. Debnath, A. Kabra |

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 |

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

Tripartite entanglement and nonlocality in 3-qubit states University of Calgary | Presentation | 2008-08-23 | S. Ghose, N. Sinclair |

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 |

Studying chaos, entanglement and decoherence in the quantum kicked top with cold atomsWe propose and analyze an experiment to study the dynamics of the quantum kicked top using cold Cesium atoms interacting with laser and magnetic fields. This would be the first experimental realization of this well known chaotic system in a deeply quantum regime, and would allow detailed studies of the effects of chaos on entanglement and decoherence. These studies are of importance for understanding quantum-classical correspondence as well as for designing quantum information processing applications. We describe the process of state preparation in the system, and show how the nonlinear AC Stark shift together with a pulsed magnetic field can be used to realize the kicked top Hamiltonian. Signatures of chaos are evident in the entanglement between the electronic and nuclear spin, which can be monitored via Faraday rotation spectroscopy. We analyze and explain the predicted dynamics by decomposing the initial states into regular and chaotic Floquet eigenstates. Our accurate simulations show that dynamical signatures of chaos persist in the presence of decoherence due to photon scattering. Furthermore, chaos affects the decoherence rate itself due to the rapid mixing in phase space caused by chaotic dynamics, even in a deeply quantum regime. University of Calgary | Presentation | 2007-06-07 | S. Ghose, R. Stock, R. Lal, A. Silberfarb |

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 |

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 |

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

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

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

Quantum transport in magneto-optical double-potential wells University of Calgary | Publication | 2000-10-01 | I. H. Deutsch, P. M. Alsing, J. Grondalski, S. Ghose, D. L. Haycock, P. S. Jessen |