Observation of in-plane anomalous Hall effect associated with orbital magnetization

TL;DR

This paper reports the experimental observation of an in-plane anomalous Hall effect in magnetic Weyl semimetal EuCd$_2$Sb$_2$, revealing new ways to control Hall phenomena with in-plane magnetic fields.

Contribution

It provides the first experimental demonstration of in-plane anomalous Hall effect linked to orbital magnetization and Weyl point splitting, supported by theoretical modeling.

Findings

In-plane anomalous Hall resistance shows three-fold rotational symmetry.

The effect is related to out-of-plane Weyl points splitting.

Orbital magnetization induced by in-plane field confirmed by model calculations.

Abstract

For over a century, the Hall effect, a transverse effect under out-of-plane magnetic field or magnetization, has been a cornerstone for magnetotransport studies and applications. Modern theoretical formulation based on the Berry curvature has revealed the potential that even in-plane magnetic field can induce anomalous Hall effect, but its experimental demonstration has remained difficult due to its potentially small magnitude and strict symmetry requirements. Here we report observation of the in-plane anomalous Hall effect by measuring low-carrier density films of magnetic Weyl semimetal EuCd$_2$Sb$_2$. Anomalous Hall resistance exhibits distinct three-fold rotational symmetry for changes in the in-plane field component, and this can be understood in terms of out-of-plane Weyl points splitting or orbital magnetization induced by in-plane field, as also confirmed by model calculation. Our findings demonstrate the importance of in-plane field to control the Hall effect, accelerating materials development and further exploration of various in-plane field induced phenomena.