The character of evolution of an open quantum system is often encoded in the correlation function of the environment or, equivalently, in the spectral density function of the interaction. When the environment is heterogeneous, e.g., consists of several independent subenvironments with different spectral functions, one of the subenvironments can be considered auxiliary and used to control decoherence of the open quantum system in the remaining part of the environment. The control can be realized, for example, by adjusting the character of interaction with the subenvironment via suitable parameters of its spectral density. We investigate non-Markovian evolution of a two-level system (qubit) under influence of three independent decoherence channels: two of them have classical nature and originate from interaction with a stochastic field, and the third is a quantum channel formed by interaction with a bosonic bath. By modifying spectral densities of the channels, we study their impact on steady states of the two-level system, evolution of its density matrix, and the equilibrium emission spectra. Additionally, we investigate the impact of the rotation-wave approximation applied to the bath channel on accuracy of the results.

中文翻译：

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具有有限相关时间的玻色浴和高斯脉动环境中两能级系统的非马尔可夫动力学

开放量子系统的演化特征通常被编码为环境的相关函数，或者等效地以相互作用的光谱密度函数编码。当环境是异质的，例如由具有不同光谱函数的几个独立的子环境组成时，可以将其中一个子环境视为辅助环境，并用于控制环境其余部分中开放量子系统的退相干。可以例如通过经由其光谱密度的适当参数调节与子环境的相互作用的特征来实现控制。我们研究了在三个独立的退相干通道的影响下两级系统（qubit）的非马尔可夫演化：它们中的两个具有经典性质，起源于与随机场的相互作用，第三是通过与玻色子浴相互作用形成的量子通道。通过修改通道的光谱密度，我们研究了它们对两级系统稳态，密度矩阵的演变以及平衡发射光谱的影响。此外，我们研究了应用于浴槽的旋转波近似对结果准确性的影响。