# Topological Electronic Structure and Its Temperature Evolution in Antiferromagnetic Topological Insulator MnBi2Te4

## TL;DR

This study uses high-resolution spectroscopy to clarify the electronic structure of MnBi2Te4, an antiferromagnetic topological insulator, and explores how its electronic states evolve with temperature, revealing their interaction with magnetic phase transitions.

## Contribution

The paper provides the first detailed, high-resolution electronic structure analysis of MnBi2Te4, resolving previous controversies and demonstrating temperature-dependent behavior of surface and bulk states.

## Key findings

- Identification of topological surface states in MnBi2Te4
- Observation of temperature-dependent band evolution
- Differences in surface and bulk state behavior with temperature

## Abstract

Topological quantum materials coupled with magnetism can provide a platform for realizing rich exotic physical phenomena, including quantum anomalous Hall effect, axion electrodynamics and Majorana fermions. However, these unusual effects typically require extreme experimental conditions such as ultralow temperature or sophisticate material growth and fabrication. Recently, new intrinsic magnetic topological insulators were proposed in MnBi2Te4-family compounds - on which rich topological effects could be realized under much relaxed experimental conditions. However, despite the exciting progresses, the detailed electronic structures observed in this family of compounds remain controversial up to date. Here, combining the use of synchrotron and laser light sources, we carried out comprehensive and high resolution angle-resolved photoemission spectroscopy studies on MnBi2Te4, and clearly identified its topological electronic structures including the characteristic gapless topological surface states. In addition, the temperature evolution of the energy bands clearly reveals their interplay with the magnetic phase transition by showing interesting differences for the bulk and surface states, respectively. The identification of the detailed electronic structures of MnBi2Te4 will not only help understand its exotic properties, but also pave the way for the design and realization of novel phenomena and applications.

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Source: https://tomesphere.com/paper/1907.05119