Chaki Subhasish, Olsen Kristian Stølevik, Löwen Hartmut
Institut für Theoretische Physik II-Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany.
J Phys Condens Matter. 2025 Jan 10;37(11). doi: 10.1088/1361-648X/ada336.
We study analytically the dynamics of an anisotropic particle subjected to different stochastic resetting schemes in two dimensions. The Brownian motion of shape-asymmetric particles in two dimensions results in anisotropic diffusion at short times, while the late-time transport is isotropic due to rotational diffusion. We show that the presence of orientational resetting promotes the anisotropy to late times. When the spatial and orientational degrees of freedom are reset, we find that a non-trivial spatial probability distribution emerges in the steady state that is determined by the initial orientation, particle asymmetry and the resetting rate. When only spatial degrees of freedom are reset while the orientational degree of freedom is allowed to evolve freely, the steady state is independent of the particle asymmetry. When only particle orientation is reset, the late-time probability density is given by a Gaussian with an effective diffusion tensor, including off-diagonal terms, determined by the resetting rate. Generally, the coupling between the translational and rotational degrees of freedom, when combined with stochastic resetting, gives rise to unique behavior at late times not present in the case of symmetric particles. Considering recent developments in experimental implementations of resetting, our results can be useful for the control of asymmetric colloids, for example in self-assembly processes.
我们通过解析方法研究了二维空间中受不同随机重置方案作用的各向异性粒子的动力学。形状不对称粒子在二维空间中的布朗运动在短时间内导致各向异性扩散，而由于旋转扩散，长时间输运是各向同性的。我们表明，取向重置的存在会使各向异性持续到长时间。当空间和取向自由度都被重置时，我们发现在稳态下会出现一种非平凡的空间概率分布，它由初始取向、粒子不对称性和重置率决定。当仅重置空间自由度而允许取向自由度自由演化时，稳态与粒子不对称性无关。当仅重置粒子取向时，长时间概率密度由一个具有有效扩散张量的高斯分布给出，该张量包括由重置率决定的非对角项。一般来说，平移和旋转自由度之间的耦合，与随机重置相结合，会在长时间产生对称粒子情况下不存在的独特行为。考虑到重置实验实现的最新进展，我们的结果可能有助于控制不对称胶体，例如在自组装过程中。
