Life and death of a cold BaRb$^+$ molecule inside an ultracold cloud of Rb atoms

TL;DR

This study investigates the complex evolution of a single BaRb$^+$ molecule in an ultracold Rb atom cloud, revealing detailed processes and rates of various collisional, reactive, and radiative phenomena.

Contribution

The paper introduces new methods for discriminating ion species and states, providing a comprehensive model of molecular dynamics in ultracold environments.

Findings

Determined rates for collisional and radiative relaxation.

Identified pathways for photodissociation and chemical reactions.

Mapped the molecule's trajectory through atomic and molecular states.

Abstract

We study the evolution of a single BaRb$^+$ molecule while it continuously collides with ultracold Rb atoms. The initially weakly-bound molecule can undergo a sequence of elastic, inelastic, reactive, and radiative processes. We investigate these processes by developing methods for discriminating between different ion species, electronic states, and kinetic ion energy ranges. By comparing the measurements to model calculations we obtain a consistent description of the typical trajectory of the ion through the manifold of available atomic and molecular states. As a further result, we determine rates for collisional and radiative relaxation as well as photodissociation, spin-flip collisions, and chemical reactions.