Orbital polarization and third-order anomalous Hall effect in WTe2

Abstract

The anomalous Hall effect (AHE) has been extended into the nonlinear regime, where the Hall voltage shows higher-order response to the applied current. Nevertheless, the microscopic mechanism of the nonlinear AHE remains unclear. Here we report the orbital polarization and its induced third-order AHE in few-layer WTe2 flakes. Through angle-dependent electric measurements, it is found that the third-order AHE is quite consistent with the electric field induced polarization of orbital magnetic moment caused by the Berry connection polarizability tensor, which is further directly detected by polar reflective magnetic circular dichroism spectroscopy. The microscopic mechanisms of third-order AHE are analyzed through the scaling law, that is, the opposite orbital magnetic moments (up or down) deflect to opposite directions driven by electric field induced Berry curvature, forming the intrinsic contribution; driven by the Magnus effect of the self-rotating Bloch electrons, the opposite orbital magnetic moments are scattered towards opposite transverse directions, resulting in the skew scattering.

References in corpus (8)

• Titanic Magnetoresistance in WTe2
• Universal Scaling Behavior of Anomalous Hall Effect and Anomalous Nernst Effect in Itinerant Ferromagnets
• Quantum frequency doubling in the topological insulator Bi2Se3
• Giant $c$-axis nonlinear anomalous Hall effect in T${}_d$-MoTe${}_2$ and WTe${}_2$
• Magnetoresistance and Quantum Oscillations of an Electrostatically Tuned Semimetal-to-Metal Transition in Ultra-Thin WTe2
• Orbit-transfer torque driven field-free switching of perpendicular magnetization
• Determination of the thickness and orientation of few-layer tungsten ditelluride using polarized Raman spectroscopy
• Comment on Absence of detectable current-induced magneto-optical Kerr effects in Pt, Ta and W Appl. Phys. Lett. 109, 172402 (2016)