中国物理B ›› 2013, Vol. 22 ›› Issue (8): 80502-080502.doi: 10.1088/1674-1056/22/8/080502
高天附a b, 郑志刚c, 陈金灿b
Gao Tian-Fu (高天附)a b, Zheng Zhi-Gang (郑志刚)c, Chen Jin-Can (陈金灿)b
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.
中图分类号: (Fluctuation phenomena, random processes, noise, and Brownian motion)