Fracton-elasticity duality of two-dimensional superfluid vortex crystals: defect interactions and quantum melting

TL;DR

This paper develops a duality-based effective theory for 2D superfluid vortex crystals, analyzing defect interactions and proposing a sequence of quantum phase transitions including a vortex supersolid phase.

Contribution

It introduces a fracton-elastic duality framework to describe vortex crystals and their defect-mediated quantum melting transitions in two-dimensional superfluids.

Findings

Derived static defect interactions in vortex crystals.

Identified continuous quantum transitions involving vortex vacancies and dislocations.

Proposed a new phase sequence including a vortex supersolid during melting.

Abstract

Employing the fracton-elastic duality, we develop a low-energy effective theory of a zero-temperature vortex crystal in a two-dimensional bosonic superfluid which naturally incorporates crystalline topological defects. We extract static interactions between these defects and investigate several continuous quantum transitions triggered by the Higgs condensation of vortex vacancies/interstitials and dislocations. We propose that the quantum melting of the vortex crystal towards the hexatic or smectic phase may occur via a pair of continuous transitions separated by an intermediate vortex supersolid phase.