Rozenbaum V M, Korochkova T Ye, Chernova A A, Dekhtyar M L
Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, Kiev, Ukraine.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 1):051120. doi: 10.1103/PhysRevE.83.051120. Epub 2011 May 18.
A Brownian motor is considered which operates due to asymmetric dichotomic fluctuations of the spatially periodic asymmetric potential energy. As shown, the motion direction and stopping points of this motor are dictated by the competition between the spatial and temporal asymmetry of the potential energy (or solely by temporal asymmetry in the case that the potential energy sign fluctuates). For an asymmetric sawtooth potential, the Brownian-particle average velocity is calculated numerically as a function of certain parameters of the model, whereas the low-frequency and low-energy approximations allow the corresponding analytical relationships to be derived for an arbitrarily shaped potential profile. It is shown that temporal asymmetry is not necessary for stopping point occurrence provided that the potential profile fluctuates not only in amplitude but in shape as well. This inference is illustrated by photoinduced fluctuations of the potential energy for a number of substituted arylpyrene molecules on a substrate with symmetrically distributed charge density.
考虑一种布朗马达，它由于空间周期性不对称势能的不对称二分涨落而运行。如图所示，该马达的运动方向和停止点由势能的空间和时间不对称性之间的竞争决定（或者在势能符号波动的情况下仅由时间不对称性决定）。对于不对称锯齿形势能，布朗粒子的平均速度作为模型的某些参数的函数进行数值计算，而低频和低能量近似允许针对任意形状的势能分布导出相应的解析关系。结果表明，只要势能分布不仅在幅度上而且在形状上波动，停止点的出现就不需要时间不对称性。通过具有对称分布电荷密度的衬底上许多取代芳基芘分子的势能的光致涨落来说明这一推断。
