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arXiv 1507.03068cond-mat.stat-mechcond-mat.mes-hall
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具有涨落幅度和方向的宏观自旋的随机热力学

Stochastic thermodynamics of macrospins with fluctuating amplitude and direction

Swarnali Bandopadhyay, Debasish Chaudhuri, A. M. Jayannavar

摘要:

本文考虑了在外加磁场作用下,宏观自旋的广义朗之万动力学中的随机能量平衡和熵产生。EP使用Fokker-Planck方程计算,区分概率流的可逆和不可逆部分。由于不可逆的非平衡过程,系统熵增加,并随着热耗散到周围环境中而减少。利用时间正向轨迹和时间反演下共轭轨迹的路径概率分布,得到了全随机EP的涨落定理。我们表明,共轭轨迹的选择是至关重要的,在获得熵一样的数量,服从FT。

英文摘要:

We consider stochastic energy balance and entropy production (EP) in a generalized Langevin dynamics of macrospins, allowing for both amplitude and direction fluctuations, under external magnetic field. EP is calculated using Fokker-Planck equation, distinguishing between reversible and irreversible parts of probability currents. The system entropy increases due to irreversible non-equilibrium processes, and reduces as heat dissipates to surrounding environment. Using path probability distributions of time-forward trajectories and conjugate trajectories under time reversal, we obtain fluctuation theorems (FT) for total stochastic EP. We show that the choice of conjugate trajectories is crucial in obtaining entropy like quantities that obey FTs.

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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