Tuning the Topological Properties of the Antiferromagnetic V(Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{4}$ via Sb concentration

TL;DR

This study demonstrates how varying Sb concentration in V(Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{4}$ tunes its topological and spin Hall properties, highlighting its potential for spintronics and quantum technologies.

Contribution

It introduces a method to control topological and spin transport properties in V(Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{4}$ through Sb doping, combining experimental and theoretical analysis.

Findings

Sb concentration modulates spin Hall conductivity.

Materials exhibit strong topological insulating behavior.

Topological surface states confirmed by band inversion and invariants.

Abstract

The investigation of topological materials has uncovered groundbreaking phases of matter with significant implications for quantum technologies. Here, we explore the antiferromagnetic topological insulator family V(Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{4}$ ($x$=$0$, $0.5$, $1$), formed by introducing vanadium telluride (VTe) layers into the layered topological insulator (Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{3}$. Our results reveal the tunability of the spin Hall conductivity (SHC) and its topological contribution, quantified by the recently introduced average Spin Chern Number (ASCN), via Sb concentration. The materials' strong topological insulating behavior is established through spin-orbit coupling-induced band inversions, nontrivial $\mathbb{Z}_2$ invariants, and the presence of topological surface states. These findings position V(Bi$_{1-x}$Sb$_{x}$)$_{2}$Te$_{4}$ as promising candidates for next-generation spintronic devices and advanced quantum applications.