Quantum stirring as a sensitive probe of 1D superfluidity

TL;DR

This paper introduces quantum stirring with a laser beam as a sensitive method to detect superfluidity in a 1D Bose gas on a ring, analyzing how stirred particles reveal superfluid behavior.

Contribution

It models the stirred particle fraction using Luttinger liquid theory, showing a crossover at a critical velocity that indicates superfluidity in a strongly interacting 1D Bose system.

Findings

Fraction of stirred particles depends on velocity, interaction, and coupling.

Superfluidity is indicated by a crossover at a critical velocity.

The critical velocity is below the sound velocity, showing unique superfluid behavior.

Abstract

We propose quantum stirring with a laser beam as a probe of superfluid behavior for a strongly interacting one-dimensional Bose gas confined to a ring. Within the Luttinger liquid theory framework, we calculate the fraction of stirred particles per period as a function of the stirring velocity, the interaction strength and the coupling between the stirring beam and the bosons. The fraction of stirred particles allows to probe superfluidity of the system. We find that it crosses over at a critical velocity, lower than the sound one, from a characteristic power law at high velocities to a constant at low velocities. Some experimental issues on quantum stirring in ring-trapped condensates are discussed.