Topological viewpoint of two-dimensional group III-V and IV-IV compounds in the presence of electric field and spin-orbit coupling by density functional theory and tight-binding model

TL;DR

This study investigates how external electric fields and spin-orbit coupling influence the topological phases of 2D group III-V and IV-IV compounds using density functional theory and tight-binding models, revealing phase transitions relevant for spintronics.

Contribution

It demonstrates the impact of electric fields and spin-orbit coupling on topological invariants and phase transitions in 2D materials, establishing consistency between theoretical models.

Findings

Electric field and spin-orbit coupling induce topological phase transitions.

Critical parameter values change the topological invariant.

Good agreement between tight-binding and density functional theories.

Abstract

Using the tight-binding model and density functional theory, the topological invariant of the two-dimensional (2D) group III-V and IV-IV compounds are studied in the absence and the presence of an external perpendicular electric field and spin-orbit coupling. It will be recognized that a critical value of these parameters changes the topological invariant of 2D graphene-like compounds. The significant effects of an external electric field and spin-orbit coupling are considered to the two-center overlap integrals of the Slater-Koster model involved in band structures, changing band-gap, and tuning the topological phase transition between ordinary and quantum spin Hall regime. These declare the good consistency between two theories: tight-binding and density functional. So, this study reveals topological phase transition in these materials. Our finding paves a way to extend an effective Hamiltonian, and may instantly clear some computation aspects of the study in the field of spintronic based on the first-principles methods.