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arXiv 1407.6530cond-mat.str-elcond-mat.mes-hall
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偏离平衡态的关联量子系统中的声子动力学

Phonon dynamics in correlated quantum systems driven away from equilibrium

Eli Y. Wilner, Haobin Wang, Michael Thoss, Eran Rabani

摘要:

考虑了多体哈密顿量的一般形式,它包括相互作用的费米子系统和非相互作用的扩展费米子系统和玻色子系统。我们表明,扩展玻色子系统的精确动力学可以从减少密度矩阵的子系统单独,尽管事实上,后者只包含有关子系统的信息。该形式的优点是显而易见的:虽然简化的密度矩阵的子系统是容易获得的,该形式提供访问包含在完整的密度矩阵,这往往是难以获得的可观的。作为一个例子,我们考虑了一个扩展的Holstein模型,并研究了非平衡动力学,所谓的“反应模式”不同的模型参数。讨论了声子频率、电子-声子耦合强度和源漏偏压对双稳态声子动力学的影响。

英文摘要:

A general form of a many-body Hamiltonian is considered, which includes an interacting fermionic sub-system coupled to non-interacting extended fermionic and bosonic systems. We show that the exact dynamics of the extended bosonic system can be derived from the reduced density matrix of the sub-system alone, despite the fact that the latter contains information about the sub-system only. The advantage of the formalism is immediately clear: While the reduced density matrix of the sub-system is readily available, the formalism offers access to observables contained in the full density matrix, which is often difficult to obtain. As an example, we consider an extended Holstein model and study the nonequilibrium dynamics of the, so called, "reaction mode" for different model parameters. The effects of the phonon frequency, the strength of the electron-phonon couplings, and the source-drain bias voltage on the phonon dynamics across the bistability are discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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