标题： 窄通道中的驱动示踪剂 显示英文标题

标题： Driven tracers in narrow channels

摘要： 稳态性质的驱动示踪粒子在静止介质的狭窄二维(2D)通道中的研究。示踪粒子使系统偏离平衡，扰动密度和压力场，并使浴粒子具有非零的平均速度，在通道中产生电流。本研究分析和比较了三种探测通道约束效应的模型：第一种是简单的对称排斥过程(SSEP)，在示踪粒子的框架中计算了稳态密度分布和壁上的压力。我们表明，示踪粒子在平均速度场中表现像偶极源。然后将这个二维条带的空间结构简化为一维SSEP，在其中允许示踪粒子和浴粒子之间的位置交换。通过结合平均场理论和在不允许交换极限下的精确解，可以很好地预测示踪粒子的速度和密度场。最后，我们证明了在允许交换的一维SSEP中获得的结果也适用于狭窄通道中的过阻尼硬盘气体。SSEP参数与硬盘气体参数之间的对应关系是系统的，并且来自于简单的直观论证。我们的分析结果通过数值计算进行了验证。 显示英文摘要

摘要： Steady state properties of a driven tracer moving in a narrow two dimensional (2D) channel of quiescent medium are studied. The tracer drives the system out of equilibrium, perturbs the density and pressure fields, and gives the bath particles a nonzero average velocity, creating a current in the channel. Three models in which the confining effect of the channel is probed are analyzed and compared in this study: the first is the simple symmetric exclusion process (SSEP), for which the stationary density profile and the pressure on the walls in the frame of the tracer are computed. We show that the tracer acts like a dipolar source in an average velocity field. The spatial structure of this 2D strip is then simplified to a one dimensional SSEP, in which exchanges of position between the tracer and the bath particles are allowed. Using a combination of mean field theory and exact solution in the limit where no exchange is allowed, gives good predictions of the velocity of the tracer and the density field. Finally, we show that results obtained for the 1D SSEP with exchanges also apply to a gas of overdamped hard disks in a narrow channel. The correspondence between the parameters of the SSEP and of the gas of hard disks is systematic and follows from simple intuitive arguments. Our analytical results are checked numerically.