Collective effects in the radiation pressure force

TL;DR

This paper examines how diffuse, Mie, and cooperative scattering influence the radiation pressure force on cold atom clouds, comparing different models to experimental results and highlighting the sufficiency of incoherent scattering descriptions.

Contribution

It demonstrates that a cooperative scattering approach is not essential to explain experimental observations, emphasizing the effectiveness of incoherent models.

Findings

Diffuse scattering explains most features of the radiation pressure force.

Incoherent random walk models match experimental results well.

Cooperative scattering models are not necessary for explaining existing experiments.

Abstract

We discuss the role of diffuse, Mie and cooperative scattering on the radiation pressure force acting on the center of mass of a cloud of cold atoms. Even though a mean-field Ansatz (the `timed Dicke state'), previously derived from a cooperative scattering approach, has been shown to agree satisfactorily with experiments, diffuse scattering also describes very well most features of the radiation pressure force on large atomic clouds. We compare in detail an incoherent, random walk model for photons and a diffraction approach to the more complete description based on coherently coupled dipoles. We show that a cooperative scattering approach, although it provides a quite complete description of the scattering process, is not necessary to explain the previous experiments on the radiation pressure force.