Tunneling anomalous Hall effect in a ferroelectric tunnel junction

TL;DR

This theoretical study predicts a tunneling anomalous Hall effect in ferroelectric tunnel junctions caused by spin-orbit coupling, showing tunable and anisotropic Hall conductivity that depends on ferroelectric polarization and magnetization orientation.

Contribution

It introduces the concept of TAHE in FTJs with large SOC, demonstrating how TAHC can be controlled and used to identify SOC types, opening new avenues for device applications.

Findings

TAHE predicted in specific ferroelectric barriers with large SOC

Strong anisotropy of TAHC depending on SOC type

Reversal of ferroelectric polarization switches TAHC sign

Abstract

We report on a theoretical study on the tunneling anomalous Hall effect (TAHE) in a ferroelectric tunnel junction (FTJ), resulting from spin-orbit coupling (SOC) in the ferroelectric barrier. For ferroelectric barriers with large SOC, such as orthorhombic HfO2 and BiInO3, we predict values of the tunneling anomalous Hall conductivity (TAHC) measurable experimentally. We demonstrate strong anisotropy in TAHC depending on the type of SOC. For the SOC with equal Rashba and Dresselhaus parameters, we predict the perfect anisotropy with zero TAHC for certain magnetization orientations. The TAHC changes sign with ferroelectric polarization reversal providing a new functionality of FTJs. Conversely, measuring the TAHC as a function of magnetization orientation offers an efficient way to quantify the type of SOC in the insulating barrier. Our results provide a new insight into the TAHE and open avenues for potential device applications.