arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1009.0845quant-ph
收藏

主方程的标准形与非马氏性的刻画

Canonical form of master equations and characterization of non-Markovianity

Michael J. W. Hall, James D. Cresser, Li Li, Erika Andersson

摘要:

主方程控制着与环境相互作用的量子系统的时间演化,并且可以以各种形式书写。与时间无关或无记忆的主方程,特别是,可以在著名的林德布拉德形式。任何时间-局域主方程,不管是马尔可夫的还是非马尔可夫的,事实上也可以写成类似林德布拉德的形式。一个对角化程序的结果在一个独特的,在这个意义上规范,表示的方程,这可能是用来充分表征非马尔可夫的时间演化。最近,已经提出了几种不同的措施,反映了不同程度上,出现负退相干率的Lindblad样形式的主方程。因此,我们建议使用负的退相干率本身,因为它们出现在主方程的规范形式,完全表征非马尔可夫性。当存在多于一个的退相干通道时,这一点的优点尤其明显。我们证明了Rivas等人提出的一个度量是正则退相干率的一个令人惊讶的简单函数,并给出了一个主方程的例子,该主方程对于所有时间t>0都是非马尔可夫的,但几乎所有提出的度量都是盲目的。我们还给出了迹距离和体积措施见证非马尔可夫性的必要和充分条件,在布洛赫阻尼矩阵。

英文摘要:

Master equations govern the time evolution of a quantum system interacting with an environment, and may be written in a variety of forms. Time-independent or memoryless master equations, in particular, can be cast in the well-known Lindblad form. Any time-local master equation, Markovian or non-Markovian, may in fact also be written in a Lindblad-like form. A diagonalisation procedure results in a unique, and in this sense canonical, representation of the equation, which may be used to fully characterize the non-Markovianity of the time evolution. Recently, several different measures of non-Markovianity have been presented which reflect, to varying degrees, the appearance of negative decoherence rates in the Lindblad-like form of the master equation. We therefore propose using the negative decoherence rates themselves, as they appear in the canonical form of the master equation, to completely characterize non-Markovianity. The advantages of this are especially apparent when more than one decoherence channel is present. We show that a measure proposed by Rivas et al. is a surprisingly simple function of the canonical decoherence rates, and give an example of a master equation that is non-Markovian for all times t>0, but to which nearly all proposed measures are blind. We also give necessary and sufficient conditions for trace distance and volume measures to witness non-Markovianity, in terms of the Bloch damping matrix.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑