# Magnetically Controllable Topological Quantum Phase Transitions in Antiferromagnetic Topological Insulator MnBi$_2$Te$_4$

## TL;DR

This paper predicts magnetically controllable topological quantum phase transitions in MnBi₂Te₄, revealing how magnetic manipulation can induce various topological phases and transitions in this antiferromagnetic topological insulator.

## Contribution

It demonstrates, through first-principles calculations, that magnetic orientation control can induce multiple novel topological phases and phase transitions in MnBi₂Te₄.

## Key findings

- Magnetic orientation affects material symmetries and topological phases.
- Predicted phase transitions include AFM TI to mirror topological crystalline insulator.
- Transitions from type-II to type-I Weyl semimetal and axion to Chern insulator.

## Abstract

The recent discovery of antiferromagnetic (AFM) topological insulator (TI) MnBi$_2$Te$_4$ has triggered great research efforts on exploring novel magnetic topological physics. Based on first-principles calculations, we find that the manipulation of magnetic orientation and order not only significantly affects material symmetries and orbital hybridizations, but also results in variant new magnetic topological phases in MnBi$_2$Te$_4$. We thus predict a series of unusual topological quantum phase transitions that are magnetically controllable in the material, including phase transitions from AFM TI to AFM mirror topological crystalline insulator, from type-II to type-I topological Weyl semimetal, and from axion insulator to Chern insulator. The findings open new opportunities for future research and applications of magnetic topological materials.