# Topological Anderson insulator phase in a quasicrystal lattice

## TL;DR

This paper demonstrates that disorder can induce a topological Anderson insulator phase in a two-dimensional quasicrystal lattice, with robust edge states and quantized conductance, expanding understanding of topological phases in aperiodic systems.

## Contribution

It reveals that disorder can induce a topological phase transition in a quasicrystal lattice, supported by numerical evidence and topological index calculations.

## Key findings

- Disorder induces a transition from normal insulator to topological Anderson insulator.
- Quantized conductance plateau appears inside the energy gap due to disorder.
- Edge-localized current distributions confirm the topological nature of the disorder-induced phase.

## Abstract

Motivated by the recent experimental realization of the topological Anderson insulator and research interest on the topological quasicrystal lattices, we investigate the effects of disorder on topological properties of a two-dimensional Penrose-type quasicrystal lattice that supports the quantum spin Hall insulator (QSHI) and normal insulator (NI) phases in the clean limit. It is shown that the helical edge state of the QSHI phase is robust against weak disorder. Most saliently, it is found that disorder can induce a phase transition from NI to QSHI phase in the quasicrystal system. The numerical results based on a two-terminal device show that a quantized conductance plateau can arise inside the energy gap of NI phase for moderate Anderson disorder strength. Further, it is confirmed that the local current distributions of the disorder-induced quantized conductance plateau are located on the two edges of sample. Finally, we identify this disorder-induced phase as topological Anderson insulator phase by computing the disorder-averaged spin Bott index.