High-order AMR in two-dimensional magnetic monolayers from spin mixing

TL;DR

This paper uncovers high-order anisotropic magnetoresistance (AMR) in 2D magnetic monolayers, driven by spin mixing and Berry curvature effects, offering new insights for spintronic device design.

Contribution

It reveals the existence of high-order AMR in 2D magnetic monolayers and links it to spin mixing and Berry curvature, advancing understanding of magnetoresistance phenomena.

Findings

High-order AMR observed in Fe3GeTe2 and CrTe2 monolayers.

Spin mixing at band crossings induces significant Berry curvature.

High-order AMR can be optimized for spintronic applications.

Abstract

Anisotropic magnetoresistance (AMR) is a well-known magnetoelectric coupling phenomenon, commonly exhibiting two-fold symmetry relative to the magnetic field. In this study, we reveal the existence of high-order AMRs in two-dimensional (2D) magnetic monolayers. Based on density functional theory (DFT) calculations of Fe3GeTe2 and CrTe2 monolayers, we find that different energy bands contribute uniquely to AMR behavior. The high-order AMR is attributed to strong spin mixing at band crossing points, which induces significant Berry curvature. This curvature also contributes to the AMR for electrons with dominant spin-up or spin-down polarization characteristics. However, for electrons exhibiting strong spin mixing, the Berry curvature effect becomes nontrivial, resulting in high-order AMR. Our findings provide an effective approach to identifying and optimizing materials with high-order AMR, which is critical for designing high-performance spintronic devices.