# Surface states and Rashba-type spin polarization in antiferromagnetic MnBi$_2$Te$_4$

## TL;DR

This study investigates the surface electronic structure of antiferromagnetic MnBi₂Te₄, revealing a surface state within the bulk band gap and evidence of exchange interaction and spin-orbit coupling effects, advancing understanding of magnetic topological materials.

## Contribution

It provides experimental spin- and angle-resolved photoelectron spectroscopy data confirming theoretical predictions of surface states in MnBi₂Te₄.

## Key findings

- Identification of a surface state in the bulk band gap.
- Evidence of exchange interaction influence on surface electronic structure.
- Confirmation of spin-orbit coupling effects on surface states.

## Abstract

The layered van der Waals antiferromagnet MnBi$_2$Te$_4$ has been predicted to combine the band ordering of archetypical topological insulators such as Bi$_2$Te$_3$ with the magnetism of Mn, making this material a viable candidate for the realization of various magnetic topological states. We have systematically investigated the surface electronic structure of MnBi$_2$Te$_4$(0001) single crystals by use of spin- and angle-resolved photoelectron spectroscopy experiments. In line with theoretical predictions, the results reveal a surface state in the bulk band gap and they provide evidence for the influence of exchange interaction and spin-orbit coupling on the surface electronic structure.