# Isotropic Light vs Six-Beam Molasses for Doppler Cooling of Atoms From Background Vapor - Theoretical Comparison

## TL;DR

This paper theoretically compares isotropic light and six-beam molasses for Doppler cooling, finding equal mean cooling rates but differences in transverse forces affecting velocity capture range.

## Contribution

It provides a detailed 3D theoretical analysis highlighting the differences in force components between the two cooling schemes.

## Key findings

- Mean cooling rates are equal in both configurations.
- Transverse force component differs significantly, affecting velocity capture.
- High atomic velocities in six-beam molasses can reduce capture range.

## Abstract

We present a 3D theoretical comparison between the radiation-pressure forces exerted on an atom in an isotropic light cooling scheme and in a six-beam molasses. We demonstrate that, in the case of a background vapor where all the space directions of the atomic motion have to be considered, the mean cooling rate is equal in both configurations. Nevertheless, we also point out what mainly differentiates the two cooling techniques: the force component orthogonal to the atomic motion. If this transverse force is always null in the isotropic light case, it can exceed the radiation-pressure-force longitudinal component in the six-beam molasses configuration for high atomic velocities, hence reducing the velocity capture range.