Competitive localization of vortex lines and interacting bosons

TL;DR

This paper develops a theoretical model describing how vortex lines and interacting bosons localize or delocalize in the presence of a potential well, revealing a novel exchange-delocalization transition influenced by interactions and temperature.

Contribution

It introduces a new theoretical framework for understanding exchange-delocalization transitions of vortex lines and bosons near defects, including a specific model for two vortices and a generalization to many.

Findings

Identified a new exchange-delocalization transition for two vortices.

Calculated the transition point and its order.

Proposed a generalization to arbitrary vortex numbers.

Abstract

We present a theory for the localization of three-dimensional vortex lines or two-dimensional bosons with short-ranged repulsive interaction which are competing for a single columnar defect or potential well. For two vortices we use a necklace model approach to find a new kind of delocalization transition between two different states with a single bound particle. This exchange-delocalization transition is characterized by the onset of vortex exchange on the defect for sufficiently weak vortex-vortex repulsion or sufficiently weak binding energy corresponding to high temperature. We calculate the transition point and order of the exchange-delocalization transition. A generalization of this transition to arbitrary vortex number is proposed.