# Laser Cooling at Resonance

## TL;DR

This paper demonstrates experimentally that lithium atoms can be laser cooled at resonance, and provides a comprehensive theoretical model including atomic structure and polarization effects, supported by Monte Carlo simulations.

## Contribution

It introduces a detailed model for 3-D laser cooling at resonance in lithium atoms, incorporating all Zeeman sub-levels and polarization effects, validated by experimental data.

## Key findings

- Laser cooling achieved at exact resonance with lithium atoms.
- Good agreement between theoretical model and experimental results.
- Coherent processes are crucial for understanding the cooling mechanism.

## Abstract

We show experimentally that 3-D laser cooling of lithium atoms is achieved when the laser light is tuned exactly to resonance with the atomic transition. For a theoretical description of this surprising phenomenon we resolve to a full model which takes into account both the entire atomic structure and the laser light polarization. Here we build such a model for $^7$Li atoms cooled on the $D_{2}$-line in a $\sigma^+-\sigma^-$ laser configuration. We take all 24 Zeeman sub-levels into account and obtain good agreement with the experimental data. Moreover, by means of Monte-Carlo simulations we show that coherent processes play an important role in showing consistency between the theory and the experimental results.