Interacting Bose-condensed gases

TL;DR

This paper reviews how interactions influence Bose-condensed gases, discussing experimental phenomena like quantum droplets, supersolids, and effects of tunable contact and dipolar interactions.

Contribution

It provides a comprehensive overview of interaction effects in Bose gases, including recent experimental observations and theoretical insights into complex quantum phases.

Findings

Modification of ground state and excitation spectrum

Observation of quantum droplets and supersolids

Behavior near the Bose--Einstein condensation temperature

Abstract

We provide an overview of the effects of interactions in Bose-condensed gases. We focus on phenomena that have been explored in ultracold atom experiments, covering both tuneable contact interactions and dipolar interactions. Our discussion includes: modifications to the ground state and excitation spectrum, critical behaviour near the Bose--Einstein condensation temperature, the unitary regime where the interactions are as strong as allowed by quantum mechanics, quantum droplets in mixtures, and supersolids in dipolar gases.