Decay of Superflow Confined in Thin Torus: A Realization of Tunneling Quantum Fields

TL;DR

This paper investigates quantum phase slip nucleation in superfluids confined in a thin torus, revealing how quantum fluctuations and the torus's size influence decay rates.

Contribution

It introduces a collective coordinate method to describe quantum nucleation of phase slips and calculates the effective mass considering quantum fluctuations.

Findings

Effective mass proportional to torus circumference L

Decay rate exhibits strong exponential dependence on L

Quantum fluctuations significantly influence phase slip dynamics

Abstract

The quantum nucleation of phase slips in neutral superfluids confined in a thin torus is investigated by means of the collective coordinate method. We have devised, with numerical justification, a certain collective coordinate to describe the quantum nucleation process of a phase slip. Considering the quantum fluctuation around the local minimum of the action, we calculate the effective mass of the phase slip. Due to the coherence of the condensate throughout the torus, the effective mass is proportional to the circumference L of the torus, and the decay rate has a strong exponential L-dependence.