Intrinsic antiferromagnetic topological insulator and axion state in V2WS4

TL;DR

This paper predicts that V$_2$WS$_4$, a layered magnetic material, hosts multiple topological states including an antiferromagnetic topological insulator and axion state, with potential for experimental realization and applications.

Contribution

It introduces V$_2$WS$_4$ as a new intrinsic magnetic topological insulator with rich topological phases and high Néel temperature, expanding the material landscape for topological quantum phenomena.

Findings

V$_2$WS$_4$ exhibits intralayer ferromagnetism and interlayer antiferromagnetism.

Multiple topological states are predicted, including axion and quantum anomalous Hall states.

Néel temperature is higher than MnBi$_2$Te$_4$, promising for practical applications.

Abstract

Intrinsic magnetic topological insulators offers an ideal platform to explore exotic topological phenomena, such as axion electrodynamics, quantum anomalous Hall (QAH) effect and Majorana edge modes. However, these emerging new physical effects have rarely been experimentally observed due to the limited choice of suitable materials. Here, we predict the van der Waals layered V$_2$WS$_4$ and its related materials show intralayer ferromagnetic and interlayer antiferromagnetic exchange interactions. We find extremely rich magnetic topological states in V$_2$WS$_4$, including an antiferromagnetic topological insulator, the axion state with the long-sought quantized topological magnetoelectric effect, three-dimensional QAH state, as well as a collection of QAH insulators and intrinsic axion insulators in odd- and even-layer films, respectively. Remarkably, the N\'eel temperature of V$_2$WS$_4$ is predicted to be much higher than that of MnBi$_2$Te$_4$. These interesting predictions, if realized experimentally, could greatly promote the topological quantum physics research and application.