A Rb-Cs dual-species magneto-optical trap

TL;DR

This paper presents a dual-species 3D magneto-optical trap capable of simultaneously trapping rubidium and cesium atoms using separate laser systems and a unique beam alignment, enabling advanced ultracold atom experiments.

Contribution

The system introduces a novel dual-species MOT with non-orthogonal laser beam alignment and full horizontal optical access, facilitating complex ultracold atom research.

Findings

Achieved efficient trapping of Rb and Cs with optical depths of 3.71 and 3.45.

Utilized separate laser systems for each species with combined entry into the chamber.

Provided a versatile platform for studying interspecies interactions and Rydberg molecules.

Abstract

We describe a three-dimensional (3D) magneto-optical trap (MOT) capable of simultaneously capturing 85Rb and 133Cs atoms. Unlike conventional setups, our system utilizes two separate laser systems that are combined before entering the vacuum chamber, enabling the simultaneous trapping of two different atomic species. Additionally, in our 3D MOT configuration, two (of three) pairs of laser beams are not orthogonal to the chamber surfaces but are aligned at a 45{\deg} angle. With a total trapping laser power of 8 mW and repump laser power of 4 mW for Rb atoms, and a total trapping laser power of 7.5 mW and repump laser power of 1.5 mW for Cs atoms, we achieve optical depths (OD) of 3.71 for Rb and 3.45 for Cs, demonstrating efficient trapping for both species. Our 3D MOT setup allows full horizontal optical access to the trapped atomic ensembles without spatial interference from the trapping or repump laser beams. Moreover, the red detuning for trapping both atomic species is smaller than in traditional configurations. This system offers a versatile platform for exploring complex phenomena in ultracold atom physics, such as Rydberg molecule formation and interspecies interactions.