Flux-Driven Conductance Scaling in Disordered Topological Insulator Nanowires

TL;DR

This paper investigates how magnetic flux influences electron conductance in disordered topological insulator nanowires, revealing universal scaling behavior and flux-driven delocalization effects.

Contribution

It uncovers critical flux-dependent scaling laws and the crossover to a universal regime in disordered topological insulator nanowires, advancing understanding of flux-induced transport phenomena.

Findings

Critical scaling near half-integer flux quanta

Universal critical exponent in high disorder regime

Flux-driven delocalization transition observed

Abstract

We study quantum transport in disordered topological insulator nanowires (TINWs) under axial magnetic flux. At integer flux quanta, spin-momentum locking produces weak anti-localization peaks, while at half-integer flux quanta a helical mode protected by time-reversal symmetry (TRS) suppresses backscattering. By analyzing the flux dependence of the localization length, we uncover critical scaling around half-integer flux quanta, reflecting the competition between disorder scattering and flux-induced breaking of TRS protection. As the disorder strength increases, we identify a crossover in scaling behavior that drives the system into a regime governed by a universal critical exponent. Our results demonstrate a scaling collapse across flux values, establishing a universal regime of flux-driven delocalization in TINWs.