Dual superfluid-Bose glass critical point in two dimensions and the universal conductivity

TL;DR

This paper investigates a new critical point in two-dimensional disordered bosonic systems, calculating universal conductivity and critical exponents using a dual theory approach, and compares these with numerical and experimental data.

Contribution

It introduces a novel disordered critical point in 2D bosonic systems using a dual scalar electrodynamics framework, with calculated universal conductivity and critical exponents.

Findings

Universal conductivity at critical point: 0.25 (2e)^2/h

Correlation length exponent: 1.38

Dynamic critical exponent: 1.93

Abstract

We study the continuum version of the dual theory for a system of two-dimensional, zero temperature, disordered bosons, interacting with short range repulsion and at a commensurate density. The dual theory, which describes vortices in the bosonic ground state, and has a form of 3D classical scalar electrodynamics in random, correlated magnetic field, admits a new disordered critical point within RG calculation at fixed dimension. The universal conductivity and the critical exponents at the superfluid-Bose glass critical point are calculated as series in fixed-point values of the dual coupling constants, to the lowest non-trivial order: $\sigma_c = 0.25 (2e)^2 /h$, $\nu=1.38$ and $z=1.93$. The comparison with numerical results and experiments is discussed.