Periodic Potential In The System Affect The Asymmetry Brownian Particle Flow

In this paper,the effect of asymmetry on the current of the Brownian par-ticle in the periodic potential is discussed.It is structured as follows:The first chapter is a brief introduction of the Brownian motion and Brow-nian motor development overview and research significance,and expounds the research status and research significance of the Brownian particle current. The second chapter introduces the statistical nature of the noise and the research methods of current of Brownian particle in normal circumstances. The third chapter is the research that Ⅰ did:For asymmetric Brownian particle mod-el.analytic and simulation methods are applied to study the effect of asymmet-ric of noise and periodic potential on current. In turn, the same methods are used to discuss the effect of the two asymmetry on the current of a Brownian particle in flashing periodic potential. The conclusion and outlook are described in the last chapter.A Brownian particle in an asymmetric periodic potential and subjected to an asymmetric dichotomous noise was investigated. In the frame of Fokker-Planck equation, exact expression of current of the system was derived. By means of numerical calculations, the results indicate that:(ⅰ) As the symmetry of either potential or noise is broken, a steady current will form.(ⅱ) As the two symmetries are broken simultaneously, the current does not always appear, depending on values of symmetric parameters of the potential and the noise,(ⅲ) The current exhibits non-monotonic behavior as a function of symmetric parameter of the potential, while monotonic behavior as a function of symmetric parameter of the noise.(ⅳ) Only in the case that the potential symmetry is not broken seriously is the current greatly influenced on by the noise symmetric parameter.(ⅴ) Absolute values of the current as a function of height of potential barrier first increase then approach to saturation as the spatial potential is symmetric, while varies monotonically as the dichotomous noise is symmetric.For the Brownian particles driven by dichotomous noise in flashing periodic potential, the results gotten by the same method show that:(ⅰ) When the periodic potential is flashing, the current of system displays non-monotonic behavior with the change of noise symmetric parameter.(ⅱ)When two kinds of symmetry are destroyed, the current of the system has been in existence and appears the phenomenon of the reversal of current.(ⅲ) Either symmetry is broken, the current will exhibit the corresponding to monotonic or non-monotonic behavior.(ⅳ) With the change of potential barrier, the current shows a monotonically increasing behavior and does not change direction.In addition, the size and direction of the current of Brownian particles is mainly determined by the combination of the symmetry of periodic potential and noise. Considering only the effect of a non-symmetric periodic potential or asymmetric noise on current is defective.