Point contacts and localization in generic helical liquids

TL;DR

This paper investigates how local tunnel junctions and inhomogeneous Rashba spin-orbit coupling affect electron transport and localization in helical liquids on opposite edges of a topological insulator, revealing spin texture-dependent localization effects.

Contribution

It introduces a model for helical liquids with multiple tunnel contacts and demonstrates the impact of spin textures on localization length in the presence of Rashba coupling.

Findings

Localization length varies with spin textures.

Multiple tunnel contacts influence electron transport.

Spin inhomogeneity affects localization in helical liquids.

Abstract

We consider two helical liquids on opposite edges of a narrow two-dimensional topological insulator, which are connected by one or several local tunnel junctions. In the presence of spatially inhomogeneous Rashba spin-orbit coupling, the spin textures of the helical states on opposite edges are different. We demonstrate that this has a strong impact on the electron transport between the edges. In particular, in the case of many random tunnel contacts, the localization length depends strongly on the spin textures of the edge states.