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arXiv 2210.09035cond-mat.stat-mechcond-mat.soft
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活动驱动谐波链的Stationary states

Stationary states of activity-driven harmonic chains

Ritwick Sarkar, Ion Santra, Urna Basu

摘要:

研究了两端受两个有源库驱动的谐振子链的定态。这些水库施加相关的随机力的边界振子,最终导致系统的非平衡定态。我们考虑三个最著名的动力学的主动力,即主动Ornstein-Uhlenbeck过程,运行和翻滚过程和主动布朗过程,所有这些都有指数衰减的两点时间相关性,但非常不同的高阶波动。我们表明,无论驱动器的具体动力学,静止的速度波动是高斯性质的动力学温度保持一致的散装。此外,我们发现出现的“能量均分”在系统的大部分-体动力学温度等于在热力学极限的体势温度。我们还计算了体中瞬时能流的稳态分布,在原点附近总是呈现对数发散和非对称指数尾。特定主动驱动的特征在边界附近的振荡器的行为中变得可见。这是最突出的RTP和ABP驱动链的边界速度分布变得非高斯和电流分布有一个有限的截止。

英文摘要:

We study the stationary state of a chain of harmonic oscillators driven by two active reservoirs at the two ends. These reservoirs exert correlated stochastic forces on the boundary oscillators which eventually leads to a nonequilibrium stationary state of the system. We consider three most well-known dynamics for the active force, namely, active Ornstein-Uhlenbeck process, run-and-tumble process and active Brownian process, all of which have exponentially decaying two-point temporal correlations but very different higher order fluctuations. We show that irrespective of the specific dynamics of the drive, the stationary velocity fluctuations are Gaussian in nature with a kinetic temperature which remains uniform in the bulk. Moreover, we find the emergence of an `equipartition of energy' in the bulk of the system -- the bulk kinetic temperature equals the bulk potential temperature in the thermodynamic limit. We also calculate the stationary distribution of the instantaneous energy current in the bulk which always shows a logarithmic divergence near the origin and asymmetric exponential tails. The signatures of specific active driving become visible in the behavior of the oscillators near the boundary. This is most prominent for the RTP and ABP driven chains where the boundary velocity distributions become non-Gaussian and current distribution has a finite cutoff.

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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