Quantum Entanglement and Quantum Discord in Gaussian Open Systems
- National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, P.O. Box MG-6 (Romania)
In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable quantum entanglement and quantum discord for a system consisting of two noninteracting modes embedded in a thermal environment. Entanglement and discord are used to quantify the quantum correlations of the system. For all values of the temperature of the thermal reservoir, an initial separable Gaussian state remains separable for all times. In the case of an entangled initial Gaussian state, entanglement suppression (entanglement sudden death) takes place for non-zero temperatures of the environment. Only for a zero temperature of the thermal bath the initial entangled state remains entangled for finite times. We analyze the time evolution of the Gaussian quantum discord, which is a measure of all quantum correlations in the bipartite state, including entanglement, and show that quantum discord decays asymptotically in time under the effect of the thermal bath.
- OSTI ID:
- 21611725
- Journal Information:
- AIP Conference Proceedings, Vol. 1387, Issue 1; Conference: TIM-10: Physics conference, Timisoara (Romania), 25-27 Nov 2010; Other Information: DOI: 10.1063/1.3647062; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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