Bath-induced coherence and the secular approximation
Bath-induced coherence and the secular approximation
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DOI：
10.1103/physreva.94.012110
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发表时间：
2016-07-19
影响因子：
2.9
通讯作者：
Keeling, J.
中科院分区：
文献类型：
--
作者：
Eastham, P. R.;Kirton, P.;Keeling, J.
找到环境如何影响离散量子系统集合的有效描述，将为现代物理学的许多领域带来新的见解。马尔可夫，或当地的时间，方法很好地为个别系统，但对群体的问题出现：系统浴或系统间的耦合主导的耗散动力学？这个答案对系统内的长时间量子关联有着深远的影响。我们考虑两个玻色子模式耦合到一个浴缸。通过比较不同的马尔可夫主方程的精确解，我们发现，一个光滑的交叉的运动方程之间的主导系统间和系统浴耦合存在，但它需要一个非长期的主方程。我们预测奇异行为的动力学和非长期的运动方程的最终失败，基本上是一个失败的马尔可夫近似。我们的研究结果支持使用时间局部理论在整个交叉系统浴为主和系统间耦合为主的动态。
Finding efficient descriptions of how an environment affects a collection of discrete quantum systems would lead to new insights into many areas of modern physics. Markovian, or time-local, methods work well for individual systems, but for groups a question arises: Does system-bath or intersystem coupling dominate the dissipative dynamics? The answer has profound consequences for the long-time quantum correlations within the system. We consider two bosonic modes coupled to a bath. By comparing an exact solution against different Markovian master equations, we find that a smooth crossover of the equations of motion between dominant intersystem and system-bath coupling exists-but it requires a nonsecular master equation. We predict singular behavior of the dynamics and show that the ultimate failure of nonsecular equations of motion is essentially a failure of the Markov approximation. Our findings support the use of time-local theories throughout the crossover between system-bath-dominated and intersystem-coupling-dominated dynamics.