Spiechowicz Jakub, Kostur Marcin, Łuczka Jerzy
Institute of Physics, University of Silesia, 40-007 Katowice, Poland.
Chaos. 2017 Feb;27(2):023111. doi: 10.1063/1.4976586.
We study diffusion properties of an inertial Brownian motor moving on a ratchet substrate, i.e., a periodic structure with broken reflection symmetry. The motor is driven by an unbiased time-periodic symmetric force that takes the system out of thermal equilibrium. For selected parameter sets, the system is in a non-chaotic regime in which we can identify a non-monotonic dependence of the diffusion coefficient on temperature: for low temperature, it initially increases as the temperature grows, passes through its local maximum, next starts to diminish reaching its local minimum, and finally it monotonically increases in accordance with the Einstein linear relation. Particularly interesting is the temperature interval in which diffusion is suppressed by the thermal noise, and we explain this effect in terms of transition rates of a three-state stochastic model.
我们研究了在棘轮衬底（即具有破缺反射对称性的周期性结构）上运动的惯性布朗马达的扩散特性。该马达由一个无偏的时间周期对称力驱动，该力使系统偏离热平衡状态。对于选定的参数集，系统处于非混沌状态，在这种状态下我们可以确定扩散系数对温度的非单调依赖性：在低温时，它最初随着温度升高而增加，经过局部最大值，接着开始减小并达到局部最小值，最后根据爱因斯坦线性关系单调增加。特别有趣的是扩散被热噪声抑制的温度区间，我们用一个三态随机模型的跃迁速率来解释这种效应。
