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arXiv 1502.06704quant-phcond-mat.mes-hallcond-mat.stat-mech
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猝灭量子系统中的不可逆性和时间箭头

Irreversibility and the arrow of time in a quenched quantum system

T. B. Batalhao, A. M. Souza, R. S. Sarthour, I. S. Oliveira, M. Paternostro, E. Lutz, R. M. Serra

摘要:

不可逆性是物理学中最有趣的概念之一。虽然微观物理定律是完全可逆的,但宏观平均行为具有优先的时间方向。根据热力学第二定律,这个时间箭头与正的平均熵产生有关。利用核磁共振装置,测量了自旋为1/2的孤立系统在外加磁场快速猝灭后产生的非平衡熵,实验证明它等于微观过程与其时间反演之间的熵距离,用Kullback-Leibler散度表示.我们的结果从微观量子的角度解决了不可逆性的概念。

英文摘要:

Irreversibility is one of the most intriguing concepts in physics. While microscopic physical laws are perfectly reversible, macroscopic average behavior has a preferred direction of time. According to the second law of thermodynamics, this arrow of time is associated with a positive mean entropy production. Using a nuclear magnetic resonance setup, we measure the nonequilibrium entropy produced in an isolated spin-1/2 system following fast quenches of an external magnetic field and experimentally demonstrate that it is equal to the entropic distance, expressed by the Kullback-Leibler divergence, between a microscopic process and its time-reverse. Our result addresses the concept of irreversibility from a microscopic quantum standpoint.

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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