Realization of staircase topological Anderson phase transitions

TL;DR

This paper demonstrates that a one-dimensional nanotube can undergo multiple disorder-driven topological phase transitions, leading to a robust topological Anderson phase, confirmed through theoretical analysis, numerical simulations, and experimental topolectrical circuit measurements.

Contribution

It reveals the existence of successive topological transitions and a robust topological Anderson phase in a single system, challenging the belief that such phases vanish at high disorder.

Findings

Stepwise increase in topological invariant with disorder

Emergence of edge states at each transition

Experimental confirmation via topolectrical circuits

Abstract

One-dimensional topological Anderson insulators provide a paradigm for disorder-induced topological phases in which the underlying system turns from a trivial to a topological phase. It is widely recognized that the latter vanishes at large disorder amplitude. Here, and contrary to the general belief, we provide evidence for a successive disorder-driven topological transitions in a single-wall nanotube, culminating in a topological Anderson phase that remains unexpectedly robust at strong disorder. This phenomenon is confirmed by analysis of the corresponding topological invariant, which increases stepwise as disorder increases, giving evidence for the emergence of edge states. We experimentally implement these topological Anderson staircase phase transitions in a one-dimensional topolectrical circuit, where the persistence of edge states is revealed by node-voltage measurements. The robustness of the edge states is corroborated by numerical calculations of their localization properties. Our work opens the road to topological disordertronics, where topological phases can be tuned by disorder.