On the theory of vortex quantum tunnelling in the dense Bose superfluid helium II

TL;DR

This paper reviews the quantum tunnelling and nucleation of vortices in helium II, emphasizing a semiclassical approach for calculating tunnelling probabilities in this strongly interacting superfluid system.

Contribution

It introduces a semiclassical, large-scale method for evaluating vortex tunnelling probabilities without relying on microscopic fluid dynamics assumptions.

Findings

Semiclassical approach effectively estimates tunnelling exponents.

Geometric interpretation aids in understanding vortex nucleation.

Relevance for interpreting experimental data on helium II vortices.

Abstract

The quantum tunnelling and nucleation theory of vortices in helium II is reviewed. Arguments are given that the only reliable method to calculate tunnelling probabilities in this highly correlated, strongly interacting many-body system is the semiclassical, large scale approach for evaluation of the tunnelling exponent, which does not make any assumptions about the unknown dynamical behaviour of the fluid on microscopic scales. The geometric implications of this semiclassical theory are represented in some detail and its relevance for the interpretation of experimental data is discussed.