Modification and Control of Topological Insulator Surface States Using Surface Disorder

TL;DR

This paper demonstrates a method to control topological surface states in 3D topological insulators by introducing strong surface disorder, enabling potential device applications through patterning techniques.

Contribution

It introduces a practical approach to modulate topological transport via surface disorder depth, bridging fundamental control and device fabrication.

Findings

Surface disorder significantly affects topological surface state properties.

Control of transport properties is achievable by tuning disorder depth.

Patterned disorder can enable integrated circuit fabrication.

Abstract

We numerically demonstrate a practical means of systematically controlling topological transport on the surface of a three dimensional topological insulator, by introducing strong disorder in a layer of depth $d$ extending inward from the surface of the topological insulator. The dependence on $d$ of the density of states, conductance, scattering time, scattering length, diffusion constant, and mean Fermi velocity are investigated. The proposed control via disorder depth $d$ requires that the disorder strength be near the large value which is necessary to drive the TI into the non-topological phase. If $d$ is patterned using masks, gates, ion implantation, etc., then integrated circuits may be fabricated. This technique will be useful for experiments and for device engineering.