Electric-current control of anomalous Hall effect

TL;DR

This paper demonstrates a reversible electric-current control of the anomalous Hall effect in a 2D WTe2/Fe3GeTe2 stack, revealing a significant modulation linked to Berry-curvature dipole effects at the interface.

Contribution

It introduces a novel interfacial method to control the anomalous Hall effect via electric current, highlighting the role of Berry-curvature dipole in 2D heterostructures.

Findings

A giant >180% modulation of AHE conductivity was achieved.

The effect is interfacial and peaks with bilayer WTe2.

Charge current induces out-of-plane magnetization via Berry-curvature dipole.

Abstract

We demonstrate robust and reversible electric-current control of the anomalous Hall effect (AHE) in a two-dimensional WTe2/Fe3GeTe2 (FGT) stack. Applying a current through Td-WTe2 leads to a giant modulation of the AHE of the adjacent FGT layer, with the relative change of the AHE conductivity exceeding 180%. Control experiments show that i) the observed effect is absent in pure FGT, ii) the modulation weakens in thicker FGT films, confirming its interfacial origin, and iii) the modulation peaks for bilayer WTe2, indicating that the Berry-curvature dipole (BCD) plays the dominant role in the modulation. We propose that the charge current I generates an out-of-plane magnetization Mz via BCD in WTe2 and Mz modifies the exchange splitting of FGT via the inverse magnetic proximity effect, thereby altering its Berry curvature and nontrivially influencing the AHE. The demonstrated method of AHE control offers new possibilities for magnetism control, i.e., for the study of AHE-transistors as well as electric-current control of quantum magnets, especially magnetic insulators.