Persistent currents in ultracold gases

TL;DR

This review discusses the study of persistent currents in ultracold gases, highlighting recent experimental advances and their implications for quantum science and potential technological applications.

Contribution

It provides a comprehensive overview of how ultracold atom systems enable new insights into persistent currents and related quantum phenomena.

Findings

Persistent currents can be realized with ultracold bosons and fermions.

Ultracold gases allow control over quantum coherence and vortex dynamics.

Potential for developing matter-wave gyroscopes and interferometers.

Abstract

Persistent currents flowing in spatially closed tracks define one of the most iconic concepts in mesoscopic physics. They have been studied in solid-state platforms such as superfluids, superconductors and metals. Cold atoms trapped in magneto-optical toroidal circuits and driven by suitable artificial gauge fields allow us to study persistent currents with unprecedented control and flexibility of the system's physical conditions. Here, we review persistent currents of ultracold matter. Capitalizing on the remarkable progress in driving different atomic species to quantum degeneracy, persistent currents of single or multicomponent bosons/fermions, and their mixtures can be addressed within the present experimental know-how. This way, fundamental concepts of quantum science and many-body physics, like macroscopic quantum coherence, solitons, vortex dynamics, fermionic pairing and BEC-BCS crossover can be studied from a novel perspective. Finally, we discuss how persistent currents can form the basis of new technological applications like matter-wave gyroscopes and interferometers.