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arXiv 2404.04533cond-mat.stat-mechmath-phmath.MPquant-ph
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热量从热处流向冷处:孤立宏观量子系统中热化的一个简单严格例子

Heat flows from hot to cold: A simple rigorous example of thermalization in an isolated macroscopic quantum system

Hal Tasaki

AI总结:

本文构造等价于自由费米子链的弱导热一维固体玩具模型,严格证明微正则能量壳内任意初态的粗粒化能量分布会均匀化,从而无需未证假设即实现强 ETH 框架下的热化。

摘要:

在本短文中,我们讨论一个宏观量子多体系统的简单例子,其中从微正则能量壳内任意初态趋向热平衡的过程,是在不依赖任何未经证明假设的情况下得到证明的。该模型等价于一条自由费米子链,被设计为弱导热一维固体的玩具模型。我们采取现象学观点:当测得的粗粒化能量分布均匀时,即认为系统处于热平衡。这里报告的热化结果,是我们此前关于自由费米子链中不可逆膨胀结果的一个变体(也是改进)。据我们所知,这是对 von Neumann 于1929年提出、并在近期由 Goldstein、Lebowitz、Mastrodonato、Tumulka、Zanghì 以及本文作者进一步发展的平衡统计力学基础哲学的首次具体而严格的实现;该哲学即从宏观观点刻画热平衡,并利用强 ETH 来控制长时间动力学。本短文将是我关于热化的更长文章《什么是热平衡,我们如何到达那里?》中技术性最强的部分。我在此阶段公开这份文档,是因为我已经(并将)在我的一些报告中宣布这些结果。

英文摘要:

In the present note, we discuss a simple example of a macroscopic quantum many-body system in which the approach to thermal equilibrium from an arbitrary initial state in the microcanonical energy shell is proved without relying on any unproven assumptions. The model, which is equivalent to a free fermion chain, is designed to be a toy model for a weakly heat-conducting one-dimensional solid. We take a phenomenological point of view and perceive that the system is in thermal equilibrium when the measured coarse-grained energy distribution is uniform. The result on thermalization reported here is a variation (and an improvement) of our previous result on the irreversible expansion in a free fermion chain. As far as we know, this is the first concrete and rigorous realization of the philosophy on the foundation of equilibrium statistical mechanics proposed by von Neumann in 1929, and further developed recently by Goldstein, Lebowitz, Mastrodonato, Tumulka, and Zangh\`ıand the present author, namely, to characterize thermal equilibrium from a macroscopic viewpoint and to make use of the strong ETH to control the long-time dynamics. This note will be the most technical part of my longer article on thermalization, "What is thermal equilibrium and how do we get there?". I am making this document public at this stage since I have already announced (and will announce) the results at some of my talks.

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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