库仑摩擦驱动的热浴中的布朗棘轮
软凝聚态物质
2013-03-21 v2 统计力学
摘要
无偏涨落的整流，也称为棘轮效应，通常在统计非平衡条件下获得。在此，我们提出一种新的棘轮机制，其中热浴促使不对称轮子发生随机旋转，同时该轮子还因固 - 固接触而受到库仑摩擦。数值模拟和解析计算表明，摩擦会诱导净漂移。如果将热浴替换为颗粒气体，众所周知的颗粒棘轮效应也会介入，并在高碰撞率下占据主导地位。对于我们选择的轮子形状，颗粒效应的作用方向与摩擦诱导的力矩方向相反，导致随着碰撞率的增加，棘轮方向发生反转。我们实现了一项新的颗粒棘轮实验，观察到了这两种棘轮效应，以及它们在交叉点处的预测反转。我们的发现为在平衡流体中仅基于纳米摩擦实现微米和亚微米级布朗马达铺平了道路。
引用
@article{arxiv.1211.4209,
title = {Brownian ratchet in a thermal bath driven by Coulomb friction},
author = {A. Gnoli and A. Petri and F. Dalton and G. Gradenigo and G. Pontuale and A. Sarracino and A. Puglisi},
journal= {arXiv preprint arXiv:1211.4209},
year = {2013}
}
备注
main paper: 4 pages and 4 figures; supplemental material joined at the end of the paper; a movie of the experiment can be viewed http://www.youtube.com/watch?v=aHrdY4BC71k ; all the material has been submitted for publication [new version with substantial changes in the order of the presentation of the results; differences with previous works have been put in evidence]