Persistent currents in a circular array of Bose-Einstein condensates

TL;DR

This paper investigates the stability of persistent currents in a ring of Bose-Einstein condensates, identifying conditions under which these currents are stable or unstable based on system parameters and excitations.

Contribution

It provides a theoretical analysis of the stability criteria for persistent currents in a circular array of BECs, including characterization of instabilities and experimental implications.

Findings

Only certain currents are stable depending on system parameters.

Instabilities are linked to quasiparticle excitations.

Experimental setups can test the stability predictions.

Abstract

A ring-shaped array of Bose-Einstein condensed atomic gases can display circular currents if the relative phase of neighboring condensates becomes locked to certain values. It is shown that, irrespective of the mechanism responsible for generating these states, only a restricted set of currents are stable, depending on the number of condensates, on the interaction and tunneling energies, and on the total number of particles. Different instabilities due to quasiparticle excitations are characterized and possible experimental setups for testing the stability prediction are also discussed.