Measures for the non-Markovianity of a harmonic oscillator coupled to a discrete bath derived from numerically exact references
Measures for the non-Markovianity of a harmonic oscillator coupled to a discrete bath derived from numerically exact references
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DOI：
10.1140/epjd/e2014-50727-8
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发表时间：
2015-02
期刊：
影响因子：
--
通讯作者：
U. Lorenz;P. Saalfrank
中科院分区：
文献类型：
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作者：
U. Lorenz;P. Saalfrank
物理学和化学中的系统浴问题通常用马尔可夫主方程来描述。然而，马尔可夫近似，即，忽略浴记忆效应并不总是合理的，在文献中已经提出了不同的非马尔可夫度量来判断这种近似的有效性。在这里，我们计算几个可计算的措施，非马尔可夫的非平凡问题的谐振子耦合到大量的浴振荡器。多解含时Hartree方法用于提供系统浴薛定谔方程的数值收敛解，从中可以计算出适当的量。特别是，我们考虑各种初始状态的跟踪距离和量子不和谐的基础上的措施。这些量在量子光学中通常遇到的二能级和其他小模型系统的情况下被证明是有用的，但对于与化学物理相关的更复杂的模型系统来说，解释起来就不那么简单了。图形摘要
AbstractSystem-bath problems in physics and chemistry are often described by Markovian master equations. However, the Markov approximation, i.e., neglect of bath memory effects is not always justified, and different measures of non-Markovianity have been suggested in the literature to judge the validity of this approximation. Here we calculate several computable measures of non-Markovianity for the non-trivial problem of a harmonic oscillator coupled to a large number of bath oscillators. The Multi Configurational Time Dependent Hartree method is used to provide a numerically converged solution of the system-bath Schrödinger equation, from which the appropriate quantities can be calculated. In particular, we consider measures based on trace-distances and quantum discord for a variety of initial states. These quantities have proven useful in the case of two-level and other small model systems typically encountered in quantum optics, but are less straightforward to interpret for the more complex model systems that are relevant for chemical physics.Graphical abstract