Electric field tuning of the anomalous Hall effect at oxide interfaces

Sayantika Bhowal,Sashi Satpathy

doi:10.1038/s41524-019-0198-8

Abstract

Anomalous Hall effect is the phenomenon where the transport properties of the spin-polarized electrons are governed by the spin-orbit coupling that couples the orbital and spin degrees of freedom of the electron. Here we show that the anomalous Hall effect at a magnetic interface with strong spin-orbit coupling can be tuned with an external electric field. By altering the strength of the inversion symmetry breaking, the electric field changes the Rashba interaction, which in turn modifies the magnitude of the Berry curvature, the central quantity in determining the anomalous Hall conductivity. The effect is illustrated with a square lattice model, which yields a quadratic dependence of the anomalous Hall conductivity for small electric fields. Explicit density-functional calculations were performed for the recently grown iridate interface, viz., the (SrIrO3)1/(SrMnO3)1 (001) structure, both with and without an electric field, which show a strong electric field dependence. The effect may be potentially useful in spintronics applications.

Highlights

The anomalous Hall effect (AHE) occurs in solids with broken timereversal symmetry, such as the ferromagnets, as a result of the spin-orbit coupling (SOC)
The effect was noticed in the original work of Hall himself,[1,2] the explanation of the phenomenon came from the seminal paper of Karplus and Luttinger,[3] where they identified the anomalous contribution to arise from the SOC, which results in the left-right asymmetry in the scattering of the spin-polarized electrons
This results in electron doped SMO and hole doped SIO, which leads to an emergent ferromagnetism at the interface

Summary

Introduction

The anomalous Hall effect (AHE) occurs in solids with broken timereversal symmetry, such as the ferromagnets, as a result of the spin-orbit coupling (SOC). The computed values of the Berry curvature using these expressions for the TB model in absence and presence of electric field are shown, f respectively, from which it is clear that the band crossing points have the dominant contributions to the

Results

Conclusion