Evidence of robust 2D transport and Efros-Shklovskii variable range hopping in disordered topological insulator (BiSe) nanowires.

We report the experimental observation of variable range hopping conduction in focused-ion-beam (FIB) fabricated ultra-narrow nanowires of topological insulator (BiSe). The value of the exponent (d + 1) in the hopping equation was extracted as [Formula: see text]for different widths of nanowires, which is the proof of the presence of Efros-Shklovskii hopping transport mechanism in a strongly disordered system. High localization lengths (0.