Statistical description of small quantum systems beyond the weak-coupling limit.
Statistical description of small quantum systems beyond the weak-coupling limit.
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DOI：
10.1103/physreve.86.011115
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发表时间：
2012-06
期刊：
影响因子：
--
通讯作者：
Wen-ge Wang
中科院分区：
文献类型：
--
作者：
Wen-ge Wang
导出了小量子系统的统计描述的显式表达式，这些系统相对弱且仅与环境的一小部分直接耦合。导出的表达式具有标准形式，但它是由所研究系统的重归一化的自哈密顿量给出的，该表达式适当地考虑了系统-环境相互作用的影响。在系统具有窄谱且环境足够大的情况下，对自哈密顿量的修正通常具有平均场特征，由相互作用哈密顿量的环境平均值给出。在其他情况下，修正可能超出平均场近似。
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.