Metal-insulator transition in a two-dimensional system of chiral unitary class

Abstract

We perform a numerical investigation of Anderson metal-insulator transition (MIT) in a two-dimensional 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 $\ensuremath{\sigma}$-model renormalization-group theory where MIT is driven by proliferation of vortices. We determine the phase diagram and find an apparent nonuniversality 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 $\ensuremath{\nu}$ is estimated as $\ensuremath{\nu}=1.55\ifmmode\pm\else\textpm\fi{}0.1$.