Nature of continuous phase transitions in interacting topological insulators

TL;DR

This paper investigates how Hubbard repulsion influences quantum spin Hall effects in 2D lattice models, revealing a continuous phase transition with distinct universality class behaviors.

Contribution

It provides numerical evidence for a continuous quantum phase transition in interacting topological insulators, exploring different universality classes through advanced simulations.

Findings

Evidence of continuous quantum phase transition between QSHE and trivial phase

Finite-size scaling suggests Ising or XY universality classes

Numerical methods include exact diagonalization and DMRG

Abstract

We revisit the effects of the Hubbard repulsion on quantum spin Hall effects (QSHE) in two-dimensional quantum lattice models. We present both unbiased exact diagonalization and density-matrix renormalization group simulations with numerical evidences for a continuous quantum phase transition (CQPT) separating QSHE from the topologically trivial antiferromagnetic phase. Our numerical results suggest that, the nature of CQPT exhibits distinct finite-size scaling behaviors, which may be consistent with either Ising or XY universality classes for different time-reversal symmetric QSHE systems.