Single Cs Atoms as Collisional Probes in a large Rb Magneto-Optical Trap

TL;DR

This study uses single Cs atoms in a Rb magneto-optical trap to investigate inter-species collisions, revealing loss mechanisms and enabling precise collision parameter measurement, with potential applications as quantum probes.

Contribution

It introduces a method to analyze inter-species collisions using single Cs atoms, simplifying dynamics and enabling precise collision parameter extraction.

Findings

Single Cs atoms reveal light-induced loss mechanisms.

Majority Rb system remains unaffected by Cs atoms.

Precise Rb-Cs collision parameter obtained.

Abstract

We study cold inter-species collisions of Caesium and Rubidium in a strongly imbalanced system with single and few Cs atoms. Observation of the single atom fuorescence dynamics yields insight into light-induced loss mechanisms, while both subsystems can remain in steady-state. This significantly simplifies the analysis of the dynamics, as Cs-Cs collisions are effectively absent and the majority component remains unaffected, allowing us to extract a precise value of the Rb-Cs collision parameter. Extending our results to ground state collisions would allow to use single neutral atoms as coherent probes for larger quantum systems.