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arXiv 1007.1826cond-mat.stat-mechcond-mat.mes-hall
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含时粒子输运的瞬态涨落关系

Transient fluctuation relations for time-dependent particle transport

A. Altland, A. De Martino, R. Egger, B. Narozhny

摘要:

我们考虑粒子输运的影响下,随时间变化的驱动力,涨落关系连接的统计对时间反转的物理观测量的演变。在许多“介观”输运过程中,有效的多粒子动力学主要是经典的,而控制粒子运动的微观速率是量子力学的起源。在这里,我们采用随机路径积分的方法作为一个最佳的工具来探测在这样的应用中的波动统计。随机路径积分描述了Keldysh量子非平衡场论的经典极限,封装了微观粒子交换率的量子起源。动力学上,它相当于一个传输主方程,这是一个形式主义一般足以描述许多实际应用的兴趣。我们应用随机路径积分推导出一般的功能波动关系的电流引起的随时间变化的力量。我们表明,这种设置所隐含的连续测量过程不会危及量子涨落关系的推导。虽然在许多情况下,一个完整的随时间变化的电流分布的波动关系可能包含过多的信息,我们制定了一些减少的关系,并证明其应用介观运输。例子包括传输电荷的分布,在那里我们表明,推导的波动关系需要结合监测的统计数据的收费和工作。

英文摘要:

We consider particle transport under the influence of time-varying driving forces, where fluctuation relations connect the statistics of pairs of time reversed evolutions of physical observables. In many "mesoscopic" transport processes, the effective many-particle dynamics is dominantly classical, while the microscopic rates governing particle motion are of quantum-mechanical origin. We here employ the stochastic path integral approach as an optimal tool to probe the fluctuation statistics in such applications. Describing the classical limit of the Keldysh quantum nonequilibrium field theory, the stochastic path integral encapsulates the quantum origin of microscopic particle exchange rates. Dynamically, it is equivalent to a transport master equation which is a formalism general enough to describe many applications of practical interest. We apply the stochastic path integral to derive general functional fluctuation relations for current flow induced by time-varying forces. We show that the successive measurement processes implied by this setup do not put the derivation of quantum fluctuation relations in jeopardy. While in many cases the fluctuation relation for a full time-dependent current profile may contain excessive information, we formulate a number of reduced relations, and demonstrate their application to mesoscopic transport. Examples include the distribution of transmitted charge, where we show that the derivation of a fluctuation relation requires the combined monitoring of the statistics of charge and work.

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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