Coulomb Friction Driving Brownian Motors

作     者：Alessandro Manacorda Andrea Puglisi Alessandro Sarracino 

作者机构：Dipartimento di FisicaUniversità "Sapienza"p.le A.Moro 200185 RomeItaly Istituto dei Sistemi Complessi - CNR and Dipartimento di FisicaUniversità "Sapienza"p.le A.Moro 200185 RomeItaly Kavli Institute for Theoretical Physics Chinathe Chinese Academy of Sciences Laboratoire de Physique Théorique de la Matière CondenséeCNRS UMR 7600case courrier 121Université Paris 64Place Jussieu75255 Paris CedexFrance 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2014年第61卷第10期

页      面：505-513页

核心收录：

学科分类：08[工学] 080101[工学-一般力学与力学基础] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the "Granular-Chaos" project funded by the Italian MIUR under the FIRB-IDEAS grant number RBID08Z9JE 

主　　题：Brownian motors ratchet effect Coulomb friction 

摘      要：We review a family of models recently introduced to describe Brownian motors under the influence of Coulomb friction, or more general non-linear friction laws. It is known that, if the heat bath is modeled as the usual Langevin equation(linear viscosity plus white noise), additional non-linear friction forces are not sufficient to break detailed balance, i.e. cannot produce a motor effect. We discuss two possibile mechanisms to elude this problem. A first possibility, exploited in several models inspired to recent experiments, is to replace the heat bath s white noise by a collisional noise, that is the effect of random collisions with an external equilibrium gas of particles. A second possibility is enlarging the phase space, e.g. by adding an external potential which couples velocity to position, as in a Klein–Kramers equation. In both cases, non-linear friction becomes sufficient to achieve a non-equilibrium steady state and, in the presence of an even small spatial asymmetry, a motor effect is produced.