混合手征活性粒子在时间延迟反馈下的扩散和分离  

Diffusion and separation of binary mixtures of chiral active particles driven by time-delayed feedback

作　　者：廖晶晶 蔺福军[1,3] Liao Jing-Jing;Lin Fu-Jun(School of Science,Jiangxi University of Science and Technology,Ganzhou 341000,China;College of Applied Science,Jiangxi University of Science and Technology,Ganzhou 341000,China;School of Physics and Telecommunication Engineering,South China Normal University,Guangzhou 510006,China)

机构地区：[1]江西理工大学理学院,赣州341000 [2]江西理工大学应用科学学院,赣州341000 [3]华南师范大学物理与电信工程学院,广州510006

出　　处：《物理学报》2020年第22期293-303,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11905086,11804131);江西省自然科学基金(批准号:20192BAB212006);江西省教育厅科技项目(批准号:GJJ191598,GJJ191599)资助的课题。

摘　　要：在二维空间内,考虑周期性边界条件,提出了一种用时间延迟反馈分离混合手征活性粒子的新方法.当系统引入时间延迟反馈时,手征活性粒子动力学特征发生明显改变.通过调节外加时间延迟反馈的强度和反馈时间可以控制逆时针旋转(counterclockwise, CCW)粒子扩散受到顺时针旋转(clockwise, CW)粒子扩散的影响程度.当时间延迟反馈强度和反馈时间较大且系统参数取最优值时, CCW粒子加快旋转角速度,扩散完全由粒子相互作用决定,而CW粒子的扩散由自身参数和粒子相互作用共同决定,在此情况下, CCW粒子容易聚集形成团簇,而CW粒子加快扩散,混合手征活性粒子实现分离.Considering the periodic boundary conditions,a new prescription for separating binary mixtures of chiral active particles by time-delayed feedback in a two-dimensional square box is proposed.We investigate the angular velocity,the feedback intensity,the delayed time,the rotational diffusion coefficient,the self-propelled speed and the packing fraction as functions of the effective diffusion coefficient and the separation coefficient numerically by the extensive Brownian dynamics simulations.It is found that mixed chiral active particles be separated without time-delayed feedback,but the dynamics of chiral active particles are different obviously and mixed chiral particles can be separated when the time-delayed feedback is introduced.The particle configuration(mixing or demixing)is determined by the dominant factor of particles’diffusion.We can control the extent to which the diffusion of counterclockwise(CCW)active particles is affected by the diffusion of clockwise(CW)active particles adjusting the strength and the delayed time of the feedback.The response to the feedback for different chiral particles show different behaviors under different system parameters.When the feedback intensity is strong and the delayed time is long enough,the angular velocity of counterclockwise particles is accelerated and the diffusion of which is dominated by the interactions between particles completely.However,the angular speed of clockwise particles change little and the diffusion of which is determined by its parameters and particle interactions jointly.In this case,the counterclockwise particles aggregate to form clusters easily,and the clockwise particles diffuse quickly,therefore,the mixed chirality active particles are separated.When the feedback intensity is weak and the delayed time is short,the chirality difference between different chiral particles modulated by the feedback is smaller than the former case.The diffusions of counterclockwise particles and clockwise particles are both determined by their parameters and p

关 键 词：活性粒子 扩散 时间延迟反馈 粒子分离 

分 类 号：O572.2[理学—粒子物理与原子核物理]