Disorder driven topological phase transitions in 1D mechanical quasicrystals

TL;DR

This paper investigates how disorder in a 1D quasi-periodic environment influences topological phase transitions in a Su-Schrieffer-Heeger model, revealing stable topological Anderson insulators and re-entrant phase transitions.

Contribution

It analytically characterizes phase boundaries, localization, and mobility edges in a disordered quasi-periodic system, highlighting the stability of topological phases under chiral disorder.

Findings

Identification of phase boundary shifts due to quasi-periodic modulation

Evidence for a topological Anderson insulator phase

Discovery of re-entrant topological phase transitions

Abstract

We examine the transition from trivial to non-trivial phases in a Su-Schrieffer-Heeger model subjected to disorder in a quasi-periodic environment. We analytically determine the phase boundary, and characterize the localization of normal modes using their inverse participation ratio. We compute energy-dependent mobility edges and provide evidence for the emergence of a topological Anderson insulator within specific parameter ranges. Whereas the phase transition boundary is affected by the quasi-periodic modulation, the topologically insulating Anderson phase is stable with respect to the chiral disorder in a quasi-periodic setup. Additionally, our results also uncover a re-entrant topological phase transition from non-trivial to trivial phases for certain values of quasi-periodic modulation with fixed chiral disorder.