Directed transport of coupled Brownian ratchets with time-delayed feedback  

作　　者：高天附 郑志刚 陈金灿 

机构地区：[1]College of Physical Science and Technology, Shenyang Normal University [2]Department of Physics, Xiamen University [3]Department of Physics and the Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Studies, Beijing Normal University

出　　处：《Chinese Physics B》2013年第8期309-315,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11075016);the Fundamental Research Funds for the Central Universities,China(Grant No.201001);the Research Fund for the Doctoral Program of Higher Education,China(Grant No.20100003110007);the Science Foundation of the Educational Department of Liaoning Province,China(Grant No.L2012386)

摘　　要：A time-delayed feedback ratchet consisting of two Brownian particles interacting through the elastic spring is consid ered. The model describes the directed transport of coupled Brownian particles in an asymmetric two-well ratchet potential which can be calculated theoretically and implemented experimentally. We explore how the centre-of-mass velocity is af fected by the time delay, natural length of the spring, amplitude strength, angular frequency, external force, and the structure of the potential. It is found that the enhancement of the current can be obtained by varying the coupling strength of the delayed feedback system. When the thermal fluctuation and the harmonic potential match appropriately, directed current evolves periodically with the natural length of the spring and can achieve a higher transport coherence. Moreover, the external force and the amplitude strength can enhance the directed transport of coupled Brownian particles under certain conditions. It is expected that the polymer of large biological molecules may demonstrate a variety of novel cooperative effects in real propelling devices.A time-delayed feedback ratchet consisting of two Brownian particles interacting through the elastic spring is consid ered. The model describes the directed transport of coupled Brownian particles in an asymmetric two-well ratchet potential which can be calculated theoretically and implemented experimentally. We explore how the centre-of-mass velocity is af fected by the time delay, natural length of the spring, amplitude strength, angular frequency, external force, and the structure of the potential. It is found that the enhancement of the current can be obtained by varying the coupling strength of the delayed feedback system. When the thermal fluctuation and the harmonic potential match appropriately, directed current evolves periodically with the natural length of the spring and can achieve a higher transport coherence. Moreover, the external force and the amplitude strength can enhance the directed transport of coupled Brownian particles under certain conditions. It is expected that the polymer of large biological molecules may demonstrate a variety of novel cooperative effects in real propelling devices.

关 键 词：delayed feedback ratchet double-well ratchet potential centre-of-mass velocity unbiased time- periodic force 

分 类 号：O552.1[理学—热学与物质分子运动论] S981.1[理学—物理]