论文标题
由竞争在空间依赖的自我推动和外力驱动的活动粒子
Active particles driven by competing spatially dependent self-propulsion and external force
论文作者
论文摘要
我们研究了非均匀运动景观的竞争存在和外部束缚场如何影响活性颗粒的性质。我们采用具有周期性游泳速度曲线的活跃的Ornstein-Uhlenbeck粒子（AOUP）模型来得出位置和速度的稳态概率分布的分析近似值，并涵盖了统一的有色噪声近似以及最近开发了具有空间依赖游泳速度的潜在无效粒子理论。我们通过将活性粒子限制在谐波陷阱中，从而产生有趣的特性，例如从单峰到双峰（以及最终的多峰）空间密度的过渡，从而测试了该理论，从而产生了有趣的特性。相应地，速度分布显示出明显的与高斯形状的偏差，甚至在高动力区域中显示了双峰轮廓。我们的结果可以通过对外部磁场中主动胶体Janus颗粒的真实空间实验来确认。
We investigate how the competing presence of a nonuniform motility landscape and an external confining field affects the properties of active particles. We employ the active Ornstein-Uhlenbeck particle (AOUP) model with a periodic swim velocity profile to derive analytical approximations for the steady-state probability distribution of position and velocity, encompassing both the Unified Colored Noise Approximation and the theory of potential-free active particles with spatially dependent swim velocity recently developed. We test the theory by confining an active particle in a harmonic trap, which gives rise to interesting properties, such as a transition from a unimodal to a bimodal (and, eventually multimodal) spatial density, induced by decreasing the spatial period of the self propulsion. Correspondingly, the velocity distribution shows pronounced deviations from the Gaussian shape, even displaying a bimodal profile in the high-motility regions. Our results can be confirmed by real-space experiments on active colloidal Janus particles in external fields.
