论文标题
在关节平衡状态下存在的系统 - 环境相关性的主方程
A master equation incorporating the system-environment correlations present in the joint equilibrium state
论文作者
论文摘要
我们提出了一个通用的主方程，在系统环境耦合强度中正确到二阶，该方程考虑了初始的系统环境相关性。我们假设该系统及其环境处于关节热平衡状态，此后进行单一操作以准备所需的初始系统状态，此后，哈密顿系统也可能会改变。我们表明，初始相关的效果在二阶主方程中显示为附加术语，形式与通常的二阶术语相似，描述了量子系统中的松弛和变形。我们将此主方程应用于范式旋转玻色子模型的概括，即与谐波振荡器的共同环境相互作用的两级系统的集合，以及与共同自旋环境相互作用的两级系统的集合。我们证明，通常需要考虑初始系统 - 环境相关性，以便准确获得系统动力学。
We present a general master equation, correct to second order in the system-environment coupling strength, that takes into account the initial system-environment correlations. We assume that the system and its environment are in a joint thermal equilibrium state, and thereafter a unitary operation is performed to prepare the desired initial system state, with the system Hamiltonian possibly changing thereafter as well. We show that the effect of the initial correlations shows up in the second-order master equation as an additional term, similar in form to the usual second-order term describing relaxation and decoherence in quantum systems. We apply this master equation to a generalization of the paradigmatic spin-boson model, namely a collection of two-level systems interacting with a common environment of harmonic oscillators, as well as a collection of two-level systems interacting with a common spin environment. We demonstrate that, in general, the initial system-environment correlations need to be accounted for in order to accurately obtain the system dynamics.
