Diffusion occurs in numerous physical systems throughout nature, drawing its generality from the universality of the central limit theorem. Approximately a century ago it was realized that an extension to this type of dynamics can be obtained in the form of “anomalous” diffusion, where distributions are allowed to have heavy power-law tails. Owing to a unique feature of its momentum-dependent dissipative friction force, laser-cooled atomic ensembles can be used as a test bed for such dynamics. The interplay between laser cooling and anomalous dynamics bears deep predictive implications for fundamental concepts in both equilibrium and nonequilibrium statistical physics. The high degree of control available in cold-atom experiments allows for the parameters of the friction to be tuned, revealing transitions in the dynamical properties of the system. Rare events in both the momentum and spatial distributions are described by non-normalized states using tools adapted from infinite ergodic theory. This leads to new experimental and theoretical results that illuminate the various features of the system.

中文翻译：

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座谈会：耗散光学晶格中激光冷却原子的反常统计

扩散发生在自然界的许多物理系统中，其普遍性源自中心极限定理的普遍性。大约一个世纪前，人们意识到这种动态的扩展可以通过“异常”扩散的形式获得，其中允许分布具有严重的幂律尾部。由于其与动量相关的耗散摩擦力的独特特征，激光冷却原子系综可以用作此类动力学的测试台。激光冷却和反常动力学之间的相互作用对平衡和非平衡统计物理学的基本概念具有深刻的预测意义。冷原子实验中的高度控制允许调整摩擦参数，揭示系统动力学特性的转变。动量和空间分布中的罕见事件是使用根据无限遍历理论改编的工具通过非归一化状态来描述的。这带来了新的实验和理论结果，阐明了系统的各种特征。