Realization of unconventional staircase topological Anderson phase transitions

Abstract

Topological Anderson insulators provide a paradigm for disorder-induced topology, in which the underlying system turns from a trivial to a topological phase. It is widely recognized that the latter disappears at large disorder amplitude. Here, and contrary to the general belief, we provide evidence for successive disorder-driven topological transitions ending up in an unconventional topological Anderson phase that remains unexpectedly robust at strong disorder. The corresponding topological invariant increases stepwise with disorder, and then saturates in the strong-disorder regime, without reverting to a trivial Anderson insulator. We experimentally realize these topological Anderson staircase transitions in a one-dimensional topolectrical circuit that emulates single-wall nanotubes. Our work opens the road to topological disordertronics, in which robust topological phases can be tuned by disorder. Using a topolectrical circuit, the authors realise an unconventional disorder-tuned cascade of topological Anderson phase transitions ending up, contrary to the general belief, in an extremely robust topological phase. This work opens the gate for topological disordertronics, where topological channels can be tuned by disorder.