Topological entanglement entropy of interacting disordered zigzag graphene ribbons

TL;DR

This paper investigates the topological entanglement entropy of disordered zigzag graphene nanoribbons, revealing a universal value that indicates the disorder-free phase is critical and destabilized by disorder.

Contribution

It demonstrates that the topological entanglement entropy remains universal in disordered interacting systems, showing the critical nature of the phase and its instability due to disorder.

Findings

Topological entanglement entropy has a small universal value.

Disorder-free phase is critical and becomes unstable with disorder.

Results are independent of interaction and disorder strength.

Abstract

Interacting disordered zigzag graphene nanoribbons have fractional charges, are quasi-one-dimensional, and display an exponentially small gap. Our numerical computations showed that the topological entanglement entropy of these systems has a small finite but universal value, independent of the strength of the interaction and the disorder. The result that was obtained for the topological entanglement entropy shows that the disorder-free phase is critical and becomes unstable in the presence of disorder.