Ultracold ion-atom experiments: cooling, chemistry, and quantum effects

TL;DR

This paper reviews recent experimental progress in ultracold ion-atom systems, highlighting their potential for quantum chemistry, molecular ion creation, and quantum simulation, while discussing the challenges and techniques involved.

Contribution

It provides a comprehensive overview of experimental setups, techniques, and recent advances in observing quantum effects in ultracold ion-atom experiments.

Findings

Insights into ion-atom collision dynamics

Demonstrations of buffer gas cooling of ions

Observation of quantum effects in ion-atom interactions

Abstract

Experimental setups that study laser-cooled ions immersed in baths of ultracold atoms merge the two exciting and well-established fields of quantum gases and trapped ions. These experiments benefit both from the exquisite read-out and control of the few-body ion systems as well as the many-body aspects, tunable interactions, and ultracold temperatures of the atoms. However, combining the two leads to challenges both in the experimental design and the physics that can be studied. Nevertheless, these systems have provided insights into ion-atom collisions, buffer gas cooling of ions and quantum effects in the ion-atom interaction. This makes them promising candidates for ultracold quantum chemistry studies, creation of cold molecular ions for spectroscopy and precision measurements, and as test beds for quantum simulation of charged impurity physics. In this review we aim to provide an experimental account of recent progress and introduce the experimental setup and techniques that enabled the observation of quantum effects.