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arXiv:quant-ph/0003077 · Physical Review A

Dynamics of nonlocality for a two-mode squeezed state in a thermal environment

Hyunseok Jeong, Jinhyoung Lee, M. S. Kim

Published Mar 29, 2000• 105 citations
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Abstract

We investigate the time evolution of nonlocality for a two-mode squeezed state in a thermal environment. The initial two-mode pure squeezed state is nonlocal with a stronger nonlocality for a larger degree of squeezing. It is found that the larger the degree of initial squeezing, the more rapidly the squeezed state loses its nonlocality. We explain this by the rapid destruction of quantum coherence for the strongly squeezed state.

DOI
10.1103/physreva.61.052101

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We describe the time evolution of the quantum coherence in an open system consisting of two coupled bosonic modes embedded in a thermal reservoir. We discuss the influence of the environment in terms of the covariance matrix for initial squeezed thermal states. The coherence is quantified using the relative entropy as a measure, and its dynamics is studied in the framework of the theory of open systems based on completely positive quantum dynamical semigroups. We show that the evolution of the quantum coherence strongly depends on the initial state of the system (squeezing parameter and thermal photon numbers), the parameters characterizing the thermal reservoir (temperature and dissipation coefficient) and the intensity of the coupling between the two modes.
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