用Monte Carlo方法计算非Gauss噪声的重整流和效率

Rectifying current and efficiency of a non-Gaussian noise calculated using the Monte Carlo method

为提高分子马达的流与效率,用Monte Carlo方法研究了非Gauss噪声驱动的布朗粒子在闪烁棘轮势场中的流和效率。在无势情况下,粒子向两边对称地自由扩散,其分布密度函数偏离Gauss分布,存在一个长拖尾或大随机力分布被截断;当势恢复后,不对称的棘轮势将无规扩散整流成定向输运流。结果表明:棘轮势整流非Gauss噪声驱动的布朗马达,能获得比Gauss噪声情况大很多的流和效率;而且随着噪声参数的变化,流能发生反向现象。

The current and motion efficiency of a Brownian particle subjected to a non-Gaussian noise in a flashing ratchet was studied using the Monte Carlo method to improve Brownian motor's current and efficiency.The potential fluctuates between on and off states.During the potential off state,the particle driven by the noise diffuses freely and symmetrically in two directions.If the noise is non-Gaussian,the particle probability distribution departs from a Gaussian function with a long tail or a cut-off of a large random force.During the potential on state,directional transport is induced by the asymmetrical potential.The results show that non-Gaussian noise can induce larger currents and more efficient motion than Gaussian noise.The current direction can be reversed by varying the model parameters.