标题： 手性、约束和维度在活性物质中支配回滞转变 显示英文标题

标题： Chirality, confinement and dimensionality govern re-entrant transitions in active matter

摘要： 非平衡动力学的单个手性活性粒子是手性活性物质复杂行为的基础。 在这里，我们提出一个精确的解析框架，并通过模拟支持，以表征二维手性活性布朗粒子和三维力矩驱动对应物在谐波陷阱中的稳态。 使用福克-普朗克方程的拉普拉斯变换方法，我们推导出位移矩和超额峰度的显式表达式，提供对非高斯统计的精确探测。 我们的分析揭示了三个不同的区域：具有偏离中心峰值的双模活性状态、类似高斯的被动状态，以及仅在二维中独特的弱重尾分布。 我们表明维度起决定性作用：在二维中，增加手性会抑制活性并恢复被动行为，而在三维中力矩沿力矩轴保持活性，产生各向异性的稳态。 这些行为由简单的活性尺度参数所描述，可以映射被动相和活性相之间的边界。 我们的结果提供了具体的实验特征——包括峰度交叉、偏离中心的峰值和力矩引起的各向异性——这些特征确立了限制作为探测和控制手性和力矩驱动活性物质的强大工具。 显示英文摘要

摘要： The non-equilibrium dynamics of individual chiral active particles underpin the complex behavior of chiral active matter. Here we present an exact analytical framework, supported by simulations, to characterize the steady states of two-dimensional chiral active Brownian particles and three-dimensional torque-driven counterparts in a harmonic trap. Using a Laplace-transform approach of the Fokker-Planck equation, we derive closed-form expressions for displacement moments and excess kurtosis, providing a precise probe of non-Gaussian statistics. Our analysis reveals three distinct regimes: bimodal active states with off-center peaks, Gaussian-like passive states, and weakly heavy-tailed distributions unique to two dimensions. We show that dimensionality plays a decisive role: in two dimensions, increasing chirality suppresses activity and restores passive behavior, while in three dimensions torque preserves activity along the torque axis, producing anisotropic steady states. These behaviors are captured by simple active length-scale arguments that map the boundaries between passive and active phases. Our results offer concrete experimental signatures - including kurtosis crossovers, off-center peaks, and torque-induced anisotropy - that establish confinement as a powerful tool to probe and control chiral and torque-driven active matter.