Superfluidity in a gas of strongly-interacting bosons

TL;DR

This paper investigates the transition from Bose-Einstein condensation to the Tonks-Girardeau state in rotating bosonic gases using exact diagonalization, revealing persistent currents even without condensation.

Contribution

It provides a detailed numerical analysis of the transition between different quantum states in strongly-interacting bosonic systems in a toroidal trap.

Findings

Persistent currents exist across a wide interaction range.

Transition from BEC to Tonks-Girardeau state is characterized.

Superfluidity persists without Bose-Einstein condensation.

Abstract

We consider small systems of bosonic atoms rotating in a toroidal trap. Using the method of exact numerical diagonalization of the many-body Hamiltonian, we examine the transition from the Bose-Einstein condensed state to the Tonks-Girardeau state. The system supports persistent currents in a wide range between the two limits, even in the absence of Bose-Einstein condensation.