Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China.
Soft Matter. 2018 Oct 3;14(38):7850-7858. doi: 10.1039/c8sm01291a.
Rectification of interacting active particles is numerically investigated in a two-dimensional time-oscillating potential. It is found that the oscillation of the potential and the self-propulsion of active particles are two different types of nonequilibrium driving, which can induce net currents with opposite directions. For a given asymmetry of the potential, the direction of the transport is determined by the competition of the self-propulsion and the oscillation of the potential. There exists an optimal oscillating angular frequency (or self-propulsion speed) at which the average velocity takes its maximal positive or negative value. Remarkably, when the oscillation of the potential competes with the self-propulsion, the average velocity can change direction several times due to the change in the oscillating frequency. Especially, particles with different self-propulsion velocities will move in opposite directions and can be separated. Our results provide a novel and convenient method for controlling and manipulating the transport (or separation) of active particles.
在二维时变势中对相互作用的主动粒子的校正进行了数值研究。结果发现，势的振荡和主动粒子的自推进是两种不同类型的非平衡驱动，它们可以诱导具有相反方向的净电流。对于给定的势不对称性，输运的方向由自推进和势的振荡的竞争决定。在最佳的振荡角频率（或自推进速度）下，平均速度取其最大的正值或负值。值得注意的是，当势的振荡与自推进竞争时，由于振荡频率的变化，平均速度可以改变方向几次。特别是，具有不同自推进速度的粒子将沿相反方向移动，并可以分离。我们的结果为控制和操纵主动粒子的输运（或分离）提供了一种新颖而方便的方法。
