arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.08155cond-mat.stat-mechcond-mat.dis-nncond-mat.soft
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一维力场中活性粒子的速度和扩散常数

Velocity and diffusion constant of an active particle in a one dimensional force field

Pierre Le Doussal, Satya N. Majumdar, Gregory Schehr

摘要:

本文考虑一个具有两个速度态$\pm v_0$的翻滚粒子在一维非均匀力场$f(x)$中的运动.对于周期为$L$的任意周期$f(x)$,我们得到了其速度$V_L$和扩散常数$D_L$的精确公式.它们涉及“主动电位”,这允许定义全局偏差。在改变参数(例如外力$F$)时,动力学经历从非遍历捕获状态到各种移动状态的转变,其中一些在$V_L$对$F$曲线中具有非解析性。对于大的$L$,在存在偏置的情况下的随机景观导致异常扩散$x \sim t^μ$、$μ<1$或我们计算的具有有限速度的相位。

英文摘要:

We consider a run an tumble particle with two velocity states $\pm v_0$, in an inhomogeneous force field $f(x)$ in one dimension. We obtain exact formulae for its velocity $V_L$ and diffusion constant $D_L$ for arbitrary periodic $f(x)$ of period $L$. They involve the "active potential" which allows to define a global bias. Upon varying parameters, such as an external force $F$, the dynamics undergoes transitions from non-ergodic trapped states, to various moving states, some with non analyticities in the $V_L$ versus $F$ curve. A random landscape in the presence of a bias leads, for large $L$, to anomalous diffusion $x \sim t^μ$, $μ<1$, or to a phase with a finite velocity that we calculate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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