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arXiv 1802.10344quant-ph
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闭动力系统的几乎马氏过程

Almost Markovian processes from closed dynamics

Pedro Figueroa-Romero, Kavan Modi, Felix A. Pollock

摘要:

当处理涉及一个更大的复合封闭系统的子系统的量子过程时,通常将它们视为有效的无记忆(马尔可夫)。虽然开放系统理论告诉我们非马尔可夫过程应该是规范,但马尔可夫过程的普遍性是不可否认的。在这里,在不诉诸弱耦合的Born-Markov假设或进行任何近似的情况下,我们正式证明,当子系统与复合系统的其余部分相比足够小时,并且概率趋于指数单位时,过程接近马尔科夫过程。后者的大小。我们还表明,对于一个固定的全球系统的大小,它可能是不可能忽略非马尔可夫效应时,该过程被允许继续足够长的时间。然而,检测这些过程的非马尔可夫性通常需要非平凡的纠缠资源。我们的结果具有基础性的重要性,因为它们产生了几乎马尔可夫过程的复合封闭动力学,并获得它们,我们引入了一个新的概念,平衡,是远远强于传统的,并表明,这种更强的平衡是达到。

英文摘要:

It is common, when dealing with quantum processes involving a subsystem of a much larger composite closed system, to treat them as effectively memory-less (Markovian). While open systems theory tells us that non-Markovian processes should be the norm, the ubiquity of Markovian processes is undeniable. Here, without resorting to the Born-Markov assumption of weak coupling or making any approximations, we formally prove that processes are close to Markovian ones, when the subsystem is sufficiently small compared to the remainder of the composite, with a probability that tends to unity exponentially in the size of the latter. We also show that, for a fixed global system size, it may not be possible to neglect non-Markovian effects when the process is allowed to continue for long enough. However, detecting non-Markovianity for such processes would usually require non-trivial entangling resources. Our results have foundational importance, as they give birth to almost Markovian processes from composite closed dynamics, and to obtain them we introduce a new notion of equilibration that is far stronger than the conventional one and show that this stronger equilibration is attained.

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。

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