Non-Gaussian Velocity Distributions in Optical Lattices

TL;DR

This paper experimentally and numerically investigates the velocity distribution of atoms in optical lattices, revealing non-Gaussian features and demonstrating that double Gaussian functions best fit the data across various parameters.

Contribution

It provides the first detailed analysis of velocity distributions in optical lattices, showing non-Gaussian behavior and comparing multiple fitting functions.

Findings

Velocity distributions deviate from Gaussian profiles.

Double Gaussian fits outperform other models.

Experimental and numerical results are in good agreement.

Abstract

We present a detailed experimental study of the velocity distribution of atoms cooled in an optical lattice. Our results are supported by full-quantum numerical simulations. Even though the Sisyphus effect, the responsible cooling mechanism, has been used extensively in many cold atom experiments, no detailed study of the velocity distribution has been reported previously. For the experimental as well as for the numerical investigation, it turns out that a Gaussian function is not the one that best reproduce the data for all parameters. We also fit the data to alternative functions, such as Lorentzians, Tsallis functions and double Gaussians. In particular, a double Gaussian provides a more precise fitting to our results.