Metal-insulator transition in a 2D system of chiral unitary class

TL;DR

This paper numerically investigates the Anderson metal-insulator transition in a 2D chiral class AIII system, confirming theoretical predictions and analyzing critical behavior and phase diagram features.

Contribution

It provides a detailed numerical analysis of the MIT in 2D chiral class AIII, including phase diagram and critical exponents, aligning with sigma-model theory.

Findings

MIT driven by vortex proliferation

Localization-length exponent ν ≈ 1.55

Non-universality of parameters on the critical line

Abstract

We perform a numerical investigation of Anderson metal-insulator transition (MIT) in a twodimensional system of chiral symmetry class AIII by combining finite-size scaling, transport, density of states, and multifractality studies. The results are in agreement with the sigma-model renormalization-group theory, where MIT is driven by proliferation of vortices. We determine the phase diagram and find an apparent non-universality of several parameters on the critical line of MIT, which is consistent with the analytically predicted slow renormalization towards the ultimate fixed point of the MIT. The localization-length exponent $\nu$ is estimated as $\nu = 1.55 \pm 0.10$.