标题： 活性细胞地毯上的非高斯位移 显示英文标题

标题： Non-Gaussian displacements in active transport on a carpet of motile cells

摘要： 我们研究微米大小的粒子在运动细胞层上的动力学。 这种细胞地毯作为活性浴，通过直接的机械接触推动被动示踪粒子。 结果产生的非平衡输运表现出从超扩散到正常扩散的动力学转变。 即使在长时间测量的极限下，粒子位移分布也明显是非高斯的——不同于通常报道的菲克非高斯输运，后者在某些系统特定的相关时间之后恢复高斯性。 我们从实验数据中获得了扩散系数的分布，并引入了一个与实验观察到的非高斯统计相匹配的位移分布模型，并解释了为什么类似的输运特性预期会出现在许多复合活性物质系统中。 显示英文摘要

摘要： We study the dynamics of micron-sized particles on a layer of motile cells. This cell carpet acts as an active bath that propels passive tracer particles via direct mechanical contact. The resulting nonequilibrium transport shows a crossover from superdiffusive to normal-diffusive dynamics. The particle displacement distribution is distinctly non-Gaussian even in the limit of long measurement times -- different from typically reported Fickian yet non-Gaussian transport, for which Gaussianity is restored beyond some system-specific correlation time. We obtain the distribution of diffusion coefficients from the experimental data and introduce a model for the displacement distribution that matches the experimentally observed non-Gaussian statistics and argue why similar transport properties are expected for many composite active matter systems.