A discrete memory-kernel for multi-time correlations in non-Markovian quantum processes
A discrete memory-kernel for multi-time correlations in non-Markovian quantum processes
复制标题
非马尔可夫量子过程中多时间相关性的离散内存内核
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
F. A. Pollock
中科院分区：
文献类型：
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作者：
M. R. Jørgensen;F. A. Pollock
开放系统动力学的有效模拟对量子科学和技术具有广泛的重要意义。在这里，我们介绍了一个推广的传输张量，或离散时间记忆内核，形式主义多时间测量的情况下。转移张量方法开始计算一个开放的少体量子系统在长时间内的状态，假设只有短时间的系统轨迹可用。在这里，我们showthat转移张量方法可以扩展到过程，其中包括多个询问（例如测量）的开放系统动态，因为它的演变，使我们能够传播高阶短时相关函数到以后的时间，而无需进一步求助于底层系统环境的演变。我们的方法利用开放量子过程的过程张量描述来表示和传播动态的对象，从中可以提取任何多时间相关。作为该方法的效用的一个例子，我们研究了在范例自旋玻色子模型中系统-环境相关性的建立，并计算稳态发射光谱，充分考虑了稳态中存在的系统-环境相关性。
Efficient simulations of the dynamics of open systems is of wide importance for quantum science and tech-nology. Here, we introduce a generalization of the transfer-tensor, or discrete-time memory kernel, formalism to multi-time measurement scenarios. The transfer-tensor method sets out to compute the state of an open few-body quantum system at long times, given that only short-time system trajectories are available. Here, we showthat the transfer-tensor method can be extended to processes which include multiple interrogations (e.g. measurements) of the open system dynamics as it evolves, allowing us to propagate high order short-time correlation functions to later times, without further recourse to the underlying system-environment evolution. Our approach exploits the process-tensor description of open quantum processes to represent and propagate the dynamics in terms of an object from which any multi-time correlation can be extracted. As an illustration of the utility of the method, we study the build-up of system-environment correlations in the paradigmatic spin-boson model, and compute steady-state emission spectra, taking fully into account system-environment correlations present in the steady state.