Field Theoretical Study of Disorder in Non-Hermitian Topological Models

TL;DR

This paper introduces a quantum field theory approach to analytically study disorder effects in non-Hermitian topological models, revealing a universal transition from topological to trivial phases at high disorder levels.

Contribution

It presents a novel analytical method using quantum field theory to analyze disorder in non-Hermitian topological systems, validated by numerical simulations.

Findings

Disorder induces a topological to trivial phase transition.

Universal behavior observed across different models.

Transition occurs at about four times the energy scale of the models.

Abstract

Non-Hermitian systems have provided a rich platform to study unconventional topological phases.These phases are usually robust against external perturbations that respect certain symmetries of thesystem. In this work, we provide a new method to analytically study the effect of disorder, usingtools from quantum field theory applied to discrete models around phase-transition points. Weinvestigate two different one-dimensional models, the paradigmatic non-Hermitian SSH model andas-wave superconductor with imbalanced pairing. These analytic results are compared to numericalsimulations in the discrete models. An universal behavior is found for the two investigated models,namely that the systems are driven from a topological to a trivial phase for disorder strengths equalto about four times the energy scale of the model.