耦合到非简谐环境的开放量子系统的动力学与谱
Dynamics and spectra of open quantum systems coupled to anharmonic environments
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中文总结 AI 辅助
本文提出数值精确建模开放量子系统非简谐环境的框架，研究其对系统动力学的独特影响，发现非简谐环境可增强非马尔可夫性与能量传输，产生吸收谱新效应。
中文摘要 AI 辅助
在开放量子系统中，环境通常被建模为简谐振荡器的集合，而实际环境往往因自身的非简谐性表现出独特的非马尔可夫效应。本文提出一种数值精确建模开放量子系统中非简谐环境的框架，通过匹配准则将非简谐环境映射为等效简谐环境，得到的等效谱密度是由非简谐环境非等间距能隙产生的平移后的裸谱集合，还包含一个独特的零频项，该项因环境耦合算子对角元的非零方差，等效于作用在系统上的静态无序。同时，本文开发了一个框架，用于研究包含少量阻尼非简谐模式的环境的效应，这类环境因非高斯性导致匹配准则失效。对于连续和离散阻尼非简谐环境，本工作研究了它们对系统动力学的独特影响，包括与简谐近似相比增强的非马尔可夫性、吸收谱中的新效应，以及非简谐环境增强能量传输的潜力。
英文摘要
In open quantum systems, the environment is typically modelled as a collection of harmonic oscillators, whereas realistic environments often exhibit unique non-Markovian effects due to the anharmonicity of the environment. Here we present a framework for modelling anharmonic environments in open quantum systems numerically exactly, in which, via a matching criterion, we map the anharmonic environment onto an effective harmonic one. This results in an effective spectral density that is a collection of shifted bare spectra arising from the non-equidistant energy gaps of the anharmonic environment, along with a unique zero-frequency term that effectively acts as static disorder on the system. This is due to the non-zero variance of the diagonal of the bath coupling operator. In tandem, we develop a framework for investigating the effects of environments comprising a few damped anharmonic modes where the matching criterion fails to work due to the non-Gaussianity of the environment. For both continuous and discrete damped anharmonic environments, this work investigates their unique influence on the system's dynamics, including enhanced non-Markovianity compared to a harmonic approximation, novel effects in the absorption spectrum, and the potential for anharmonic environments to enhance energy transport.
