Effect of Rashba spin-orbit coupling on topological phases in monolayer ZnIn2Te4

TL;DR

This paper investigates how Rashba spin-orbit coupling affects the quantum spin Hall phase in monolayer ZnIn2Te4, revealing conditions for coexistence that could enhance spintronic device functionalities.

Contribution

It provides a detailed analysis of the interplay between Rashba and quantum spin Hall effects in a specific 2D topological insulator, guiding future material engineering.

Findings

Sizable Rashba spin splitting can coexist with a stable quantum spin Hall phase.

Conditions for maintaining topological protection despite Rashba effects.

Potential for enhanced spintronic functionalities in engineered 2D materials.

Abstract

The interplay of Rashba and quantum spin Hall effects in non-centrosymmetric systems presents both challenges and opportunities for spintronic applications. While Rashba spin-orbit coupling can disrupt the quantum spin Hall phase, their coexistence may enable additional spintronic functionalities by coupling spin-momentum locking in the bulk with topologically protected edge states. Using the ZnIn$_2$Te$_4$ monolayer as a case study-a predicted polar two-dimensional topological insulator-we investigate how intrinsic and Rashba spin-orbit coupling compete within a single material. Our results identify key conditions under which sizable Rashba spin splitting can coexist with a stable quantum spin Hall phase, offering guidance for engineering quantum spin Hall insulators with enhanced spintronic capabilities.