Sub-Ohmic to super-Ohmic crossover behavior in nonequilibrium quantum systems with electron-phonon interactions
Sub-Ohmic to super-Ohmic crossover behavior in nonequilibrium quantum systems with electron-phonon interactions
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DOI：
10.1103/physrevb.92.195143
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发表时间：
2015-08
影响因子：
3.7
通讯作者：
Eli Y. Wilner;Haobin Wang;M. Thoss;E. Rabani
中科院分区：
文献类型：
--
作者：
Eli Y. Wilner;Haobin Wang;M. Thoss;E. Rabani
而对于超欧姆（s> 1）谱密度，这种跃迁消失。本文研究了声子浴谱密度对扩展Holstein模型描述的电子-声子相互作用量子点非平衡动力学的影响。使用约化密度矩阵形式主义结合多层多组态时间相关的Hartree方法，我们调查的动态响应，时间尺度的松弛，以及存在多个长寿命的解决方案作为系统浴耦合的变化，从子到超欧姆的情况下。双稳性被证明是减少类似的自旋玻色子的情况下，增加权力的s。然而，其物理机制和对模型参数的依赖性，如典型的浴频率ωc和极化子位移λ是相当不同的。
at zero temperature and zero bias, while for super-Ohmic ( s> 1) spectral densities this transition disappears. In this paper, we consider the influence of the phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with electron-phonon interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of s similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ωc and the polaron shift λ are rather distinct.