# Quantum Hall effect in a bulk antiferromagnet EuMnBi$_2$ with magnetically confined two-dimensional Dirac fermions

## TL;DR

This paper reports the observation of a bulk half-integer quantum Hall effect in EuMnBi$_2$, demonstrating magnetic control over Dirac fermions and their potential for spintronic applications.

## Contribution

It presents the first observation of quantum Hall effect in a bulk antiferromagnet with magnetically confined Dirac fermions, showing magnetic order can manipulate Dirac transport.

## Key findings

- Half-integer quantum Hall effect observed in EuMnBi$_2$
- Magnetic order suppresses interlayer coupling of Dirac fermions
- High mobility of over 10,000 cm$^2$/Vs with Landau level splitting

## Abstract

For the innovation of spintronic technologies, Dirac materials, in which the low-energy excitation is described as relativistic Dirac fermions, are one of the most promising systems, because of the fascinating magnetotransport associated with the extremely high mobility. To incorporate Dirac fermions into spintronic applications, their quantum transport phenomena are desired to be manipulated to a large extent by magnetic order in a solid. We here report a bulk half-integer quantum Hall effect in a layered antiferromagnet EuMnBi$_2$, in which field-controllable Eu magnetic order significantly suppresses the interlayer coupling between the Bi layers with Dirac fermions. In addition to the high mobility more than 10,000 cm$^2$/Vs, Landau level splittings presumably due to the lifting of spin and valley degeneracy are noticeable even in a bulk magnet. These results will pave a route to the engineering of magnetically functionalized Dirac materials.