Universality classes of the Anderson transition in the three-dimensional symmetry classes AIII, BDI, C, D, and CI

We clarify universal critical properties of delocalization-localization transitions in three-dimensional unitary and orthogonal classes with particle-hole and/or chiral symmetries (classes AIII, BDI, D, C, and CI). We first introduce tight-binding models on cubic lattice that belong to these five nonstandard symmetry classes, respectively. Unlike the Bogoliubov-de Gennes Hamiltonian for superconductors, all the five models have finite areas of Fermi surfaces in the momentum space in the clean limit. Thereby, the scaling theory of the Anderson transition guarantees the presence of the delocalization-localization transitions at finite disorder strength in these models. Based on this expectation, we carry out extensive transfer matrix calculations of the Lyapunov exponents for zero-energy eigenstates of the disordered tight-binding models with quasi-one-dimensional geometry. Near the Anderson transition point, the correlation length diverges with a universal critical exponent nu. Using finite-size scaling analysis of the localization length, we determine the critical exponent of the transitions and scaling function of the (normalized) localization length in the three nonstandard unitary symmetry classes: nu(AIII) = 1.06 +/- 0.02, nu(D) = 0.87 +/- 0.03, and nu(C) = 0.996 +/- 0.012. Our result of the class C is consistent with a previous study of classical network model [M. Ortuno et al, Phys. Rev. Lett. 102, 070603 (2009)]. The critical exponents of the two nonstandard orthogonal classes are estimated as nu(CI) = 1.17 +/- 0.02 and nu(BDI) = 1.12 +/- 0.06. Our result of the class CI is consistent with another previous study of a lattice model, while the exponent of the class BDI is at variance with the previous evaluation of nodal Dirac ring model [X. Luo et al, Phys. Rev. B 101, 020202(R) (2020)].

Automated summary

This study investigates universal critical properties of delocalization-localization transitions in three-dimensional unitary and orthogonal classes with different symmetries, demonstrating the presence of these transitions with finite disorder strength. By analyzing the localization length, the critical exponent of the transitions and scaling function of the (normalized) localization length are determined. The results provide insights into the behavior of the transitions in these nonstandard symmetry classes.