The superconductor-insulator transition in 2D dirty boson systems

TL;DR

This study uses Monte Carlo simulations to analyze the universal properties and critical behavior of the superconductor-insulator transition in 2D disordered boson systems, revealing different conductivities for short- and long-range interactions.

Contribution

It provides the first comprehensive simulation-based analysis of the superconductor-insulator transition in 2D disordered boson systems with both short- and long-range Coulomb interactions.

Findings

Universal conductivity for long-range interactions: ~0.55 (2e)^2/h

Universal conductivity for short-range interactions: ~0.14 (2e)^2/h

Transition from superconducting to Bose glass phase observed

Abstract

Universal properties of the zero temperature superconductor-insulator transition in two-dimensional amorphous films are studied by extensive Monte Carlo simulations of bosons in a disordered medium. We report results for both short-range and long-range Coulomb interactions for several different points in parameter space. In all cases we observe a transition from a superconducting phase to an insulating Bose glass phase. {}From finite-size scaling of our Monte Carlo data we determine the universal conductivity $\sigma^*$ and the critical exponents at the transition. The result $\sigma^* = (0.55 \pm 0.06) (2e)^2/h$ for bosons with long-range Coulomb interaction is roughly consistent with experiments reported so far. We also find $\sigma^* = (0.14 \pm 0.03) (2e)^2/h$ for bosons with short-range interactions.