论文标题
细菌悬浮液中的胶体转运：从细菌散射到异常和扩散增强
Colloidal transport in bacteria suspensions: from bacteria scattering to anomalous and enhanced diffusion
论文作者
论文摘要
胶体结合到泳池浴中，通常显示出增强的扩散。这种运输动力学源于主动粒子和被动颗粒之间的微妙相互作用，尽管数十年来进行了激烈的研究，但仍能抵抗我们的理解。在这里，我们通过提供胶体和细菌之间单个散射事件的定量表征来解决问题的根源。根据我们的实验，我们构建了一个最小模型，该模型可以定量预测散射轨迹的几何形状，并长时间增强了胶体扩散。理论和实验之间的这种定量对抗阐明了增强运输的微观起源。碰撞仅由造成真正异常扩散的随机接触相互作用在短时间内进行，并且长时间扩散，而在任何规模上没有弹道式的状态。
Colloids coupled to a bath of swimming cells generically display enhanced diffusion. This transport dynamics stems from a subtle interplay between the active and passive particles that still resists our understanding despite decades of intense research. Here, we tackle the root of the problem by providing a quantitative characterisation of the single scattering events between a colloid and a bacterium. Based on our experiments, we build a minimal model that quantitatively predicts the geometry of the scattering trajectories, and enhanced colloidal diffusion at long times. This quantitative confrontation between theory and experiments elucidates the microscopic origin of enhanced transport. Collisions are solely ruled by stochastic contact interactions responsible both for genuine anomalous diffusion at short times and enhanced diffusion at long times with no ballistic regime at any scale.
