中国物理B ›› 2013, Vol. 22 ›› Issue (8): 80502-080502.doi: 10.1088/1674-1056/22/8/080502

• GENERAL • 上一篇    下一篇

Directed transport of coupled Brownian ratchets with time-delayed feedback

高天附a b, 郑志刚c, 陈金灿b   

  1. a College of Physical Science and Technology, Shenyang Normal University, Shenyang 110034, China;
    b Department of Physics, Xiamen University, Xiamen 361005, China;
    c Department of Physics and the Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Studies,Beijing Normal University, Beijing 100875, China
  • 收稿日期:2013-02-04 修回日期:2013-03-07 出版日期:2013-06-27 发布日期:2013-06-27
  • 基金资助:
    Project 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), and the Science Foundation of the Educational Department of Liaoning Province, China (Grant No. L2012386).

Directed transport of coupled Brownian ratchets with time-delayed feedback

Gao Tian-Fu (高天附)a b, Zheng Zhi-Gang (郑志刚)c, Chen Jin-Can (陈金灿)b   

  1. a College of Physical Science and Technology, Shenyang Normal University, Shenyang 110034, China;
    b Department of Physics, Xiamen University, Xiamen 361005, China;
    c Department of Physics and the Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Studies,Beijing Normal University, Beijing 100875, China
  • Received:2013-02-04 Revised:2013-03-07 Online:2013-06-27 Published:2013-06-27
  • Contact: Zheng Zhi-Gang, Chen Jin-Can E-mail:zgzheng@bnu.edu.cn; jcchen@xmu.edu.cn
  • Supported by:
    Project 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), and the Science Foundation of the Educational Department of Liaoning Province, China (Grant No. L2012386).

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摘要： A time-delayed feedback ratchet consisting of two Brownian particles interacting through the elastic spring is considered. 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 affected 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

Abstract: A time-delayed feedback ratchet consisting of two Brownian particles interacting through the elastic spring is considered. 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 affected 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.

Key words: delayed feedback ratchet, double-well ratchet potential, centre-of-mass velocity, unbiased time-periodic force

中图分类号:  (Fluctuation phenomena, random processes, noise, and Brownian motion)

  • 05.40.-a
05.40.Jc (Brownian motion) 02.30.Yy (Control theory)