论文标题
活动驱动的谐波链的固定状态
Stationary states of activity-driven harmonic chains
论文作者
论文摘要
我们研究了两端由两个主动储层驱动的谐波振荡器链的固定状态。这些储层在边界振荡器上施加相关的随机力,最终导致系统的非平稳状态。我们考虑了有效力量的三种最著名的动力学,即主动的Ornstein-Uhlenbeck过程,运行和击败的过程和主动的Brownian过程,所有这些过程都具有指数衰减的两点时间相关性,但高阶波动却非常不同。我们表明,无论驱动的特定动力学,固定速度波动在本质上都是高斯的,具有动力学温度,在大容量中保持均匀。此外,我们发现系统大部分的“能量均衡”的出现 - 大量动力学温度等于热力学极限中的大量潜在温度。我们还计算了整体中瞬时能量电流的固定分布,该分布总是在原点附近显示对数差异和不对称的指数尾巴。在边界附近的振荡器的行为中,特定主动驾驶的特定签名变得可见。对于RTP和ABP驱动的链条,边界速度分布变为非高斯,并且当前分布具有有限的截止,这是最突出的。
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.