Statistical description of small quantum systems beyond weak-coupling limit

Wen-ge Wang

doi:10.1103/physreve.86.011115

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arXiv · 1207.0061

Statistical description of small quantum systems beyond weak-coupling limit

Wen-ge Wang

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Abstract

An explicit expression is derived for the statistical description of small quantum systems, which are relatively-weakly and directly coupled to only small parts of their environments. The derived expression has a canonical form, but is given by a renormalized self-Hamiltonian of the studied system, which appropriately takes into account the influence of the system-environment interaction. In the case that the system has a narrow spectrum and the environment is sufficiently large, the modification to the self-Hamiltonian usually has a mean-field feature, given by an environmental average of the interaction Hamiltonian. In other cases, the modification may be beyond the mean-field approximation.

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Wen-ge Wang. 2012-08-14. Statistical description of small quantum systems beyond weak-coupling limit. https://doi.org/10.1103/physreve.86.011115

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