Random hopping fermions on bipartite lattices: Density of states, inverse participation ratios, and their correlations in a strong disorder regime

TL;DR

This paper investigates Anderson localization of non-interacting fermions with random hopping on bipartite lattices in two dimensions, revealing strong disorder effects on density of states and localization properties near the band center.

Contribution

It applies a renormalization group approach to analyze strong disorder effects on density of states and localization in bipartite lattice fermion models with linear dispersion.

Findings

Density of states exhibits non-trivial behavior at strong disorder.

Inverse participation ratios indicate enhanced localization effects.

Spatial correlations of localization measures differ from weak disorder predictions.

Abstract

We study Anderson localization of non-interacting random hopping fermions on bipartite lattices in two dimensions, focusing our attention to strong disorder features of the model. We concentrate ourselves on specific models with a linear dispersion in the vicinity of the band center, which can be described by a Dirac fermion in the continuum limit. Based on the recent renormalization group method developed by Carpentier and Le Doussal for the XY gauge glass model, we calculate the density of states, inverse participation ratios, and their spatial correlations. It turns out that their behavior is quite different from those expected within naive weak disorder approaches.