Interspecies collision-induced losses in a dual species 7Li-85Rb magneto-optical trap

TL;DR

This paper measures interspecies collision-induced loss rates in a dual-species 7Li-85Rb magneto-optical trap, analyzes their causes, and discusses methods to suppress these losses to facilitate ultracold molecule production.

Contribution

It provides the first detailed measurement of collision loss coefficients in a 7Li-85Rb MOT and explores strategies to reduce these losses for ultracold molecule formation.

Findings

Strong interspecies collision-induced losses observed in the MOTs.

Measured loss rate coefficients eta_{Li,Rb} and eta_{Rb,Li}.

Insights into ultracold collisions and loss suppression methods.

Abstract

In this article, we report the measurement of collision-induced loss rate coefficients \beta_{Li,Rb} and \beta_{Rb,Li}, and also discuss means to significantly suppress such collision induced losses. We first describe our dual-species magneto-optical trap (MOT) that allows us to simultaneously trap > 5x10^8 7Li atoms loaded from a Zeeman slower and > 2x10^8 85Rb atoms loaded from a dispenser. We observe strong interspecies collision-induced losses in the MOTs which dramatically reduce the maximum atom number achievable in the MOTs. We measure the trap loss rate coefficients \beta_{Li,Rb} and \beta_{Rb,Li}, and, from a study of their dependence on the MOT parameters, determine the cause for the losses observed. Our results provide valuable insights into ultracold collisions between 7Li and 85Rb, guide our efforts to suppress collision induced losses, and also pave the way for the production of ultracold 7Li85Rb molecules.