Study of light-assisted collisions between a few cold atoms in a microscopic dipole trap

TL;DR

This study investigates light-assisted collisions among a few cold Rb87 atoms in a microscopic dipole trap, measuring heating and loss rates, revealing large two-body loss rates influenced by trap depth and excitation light parameters.

Contribution

It provides precise measurements of one-body heating and two-body loss rates in a microscopic trap with few atoms, highlighting the dependence on experimental conditions.

Findings

Two-body loss rate can exceed 10^{-8} cm^{3}.s^{-1}.

Loss rates vary rapidly with trap depth and excitation light parameters.

Single-atom control enables accurate measurement of collision dynamics.

Abstract

We study light-assisted collisions in an ensemble containing a small number (~3) of cold Rb87 atoms trapped in a microscopic dipole trap. Using our ability to operate with one atom exactly in the trap, we measure the one-body heating rate associated to a near-resonant laser excitation, and we use this measurement to extract the two-body loss rate associated to light-assisted collisions when a few atoms are present in the trap. Our measurements indicate that the two-body loss rate can reach surprisingly large values beta>10^{-8} cm^{3}.s^{-1} and varies rapidly with the trap depth and the parameters of the excitation light.