Momentum distribution of atoms in one-dimensional Raman cooling with arbitrary coherent population transfer

TL;DR

This paper provides an exact analytical expression for the momentum distribution of atoms after multiple 1D Raman cooling cycles, demonstrating flexible pulse design and the possibility of subrecoil cooling regardless of specific pulse parameters.

Contribution

It introduces a comprehensive analytical model for atomic momentum distribution in 1D Raman cooling, accounting for optical pumping and showing subrecoil cooling is broadly achievable.

Findings

Analytical form for momentum distribution after Raman cooling

Flexible pulse profiles do not hinder cooling efficiency

Subrecoil cooling is generally possible regardless of pulse specifics

Abstract

We derive an exact and analytical form for the cold-atom momentum distribution after a large number of one-dimensional (1D) Raman cooling cycles has been applied. Our result shows that one can select pulse profiles and lengths rather freely in order to obtain efficient cooling. Our approach takes into account optical pumping (resonant excitation followed by spontaneous emission) as an intergral part of the process, and it is noted that it does not affect the final momentum distribution. Thus subrecoil cooling is possible in general, and not just for carefully selected combinations of pulse forms and durations.