Chemistry of a light impurity in a Bose-Einstein condensate

TL;DR

This paper explores how impurities in ultracold gases form polarons and how their dressing influences chemical reactivity, revealing that many-body effects can induce Efimov resonances and related chemical phenomena.

Contribution

It demonstrates that three-body correlations cause polaron instability and connect to Efimov physics, highlighting the impact of many-body effects on impurity chemistry in ultracold gases.

Findings

Three-body correlations induce polaron instability.

Efimov resonance is shifted by many-body effects.

Polaron formation stimulates Efimov-related chemistry.

Abstract

In ultracold atomic gases, a unique interplay arises between phenomena known from condensed matter physics, few-body physics and chemistry. Similar to an electron in a solid, an impurity in an ultracold gas can get dressed by excitations from the medium, forming a quasiparticle called the polaron. We study how dressing of an impurity leads to a modification of its chemical reactivity. Using a Gaussian state variational method in the frame of the impurity, we demonstrate that three-body correlations lead to an instability of the polaron. This instability is connected to an Efimov resonance, but shifted to smaller interactions by many-body effects, showing that polaron formation stimulates Efimov physics and the associated chemistry.