Anomalous statistics of lasercooled atoms in dissipative optical lattices
Abstract
In this Colloquium we discuss the anomalous kinetics of atoms in dissipative optical lattices, focusing on the ``Sisyphus" laser cooling mechanism. The cooling scheme induces a friction force that decreases to zero for high atomic momentum, which in turn leads to unusual statistical features. We study, using a FokkerPlanck equation describing the semiclassical limit of the system, the shallow optical lattice regime where the momentum distribution of the particles is heavytailed and the spatial diffusion is anomalous. As the depth of the optical lattice is tuned, transitions in the dynamical properties of the system occur, for example a transition from Gaussian diffusion to a Lévy walk and the breakdown of the GreenKubo formula for the diffusion constant. Rare events, in both the momentum and spatial distributions, are described by nonnormalized states, with tools adapted from infinite ergodic theory. We present experimental observations and elementary explanations for the physical mechanisms of cooling that lead to these anomalous behaviors, comparing theory with available experimental and numerical data.
 Publication:

arXiv eprints
 Pub Date:
 July 2021
 arXiv:
 arXiv:2107.09526
 Bibcode:
 2021arXiv210709526A
 Keywords:

 Condensed Matter  Statistical Mechanics;
 Physics  Atomic Physics;
 Quantum Physics