Magnetotransport in Layered Dirac Fermion System Coupled with Magnetic Moments

TL;DR

This paper presents a theoretical study of magnetotransport in EuMnBi2, revealing how Dirac fermions, localized magnetic moments, and spin-orbit coupling interact to produce observed magnetic and transport phenomena.

Contribution

It introduces a simplified interlayer hopping model that captures key features of EuMnBi2's magnetotransport behavior, linking valley splitting to magnetic hysteresis.

Findings

Hysteresis explained by valley splitting from spin-orbit coupling and magnetic field.

Model reproduces experimental magnetotransport features.

Interplay among Dirac fermions, magnetic moments, and spin-orbit coupling is crucial.

Abstract

We theoretically investigate the magnetotransport of Dirac fermions coupled with localized moments to understand the physical properties of the Dirac material EuMnBi$_2$. Using an interlayer hopping form, which simplifies the complicated interaction between the layers of Dirac fermions and the layers of magnetic moments in EuMnBi$_2$, the theory reproduces most of the features observed in this system. The hysteresis observed in EuMnBi$_2$ can be caused by the valley splitting that is induced by the spin-orbit coupling and the external magnetic field with the molecular field created by localized moments. Our theory suggests that the magnetotransport in EuMnBi$_2$ is due to the interplay among Dirac fermions, localized moments, and spin-orbit coupling.