Electric-field control of anomalous and topological Hall effects in oxide bilayer thin films

TL;DR

This study demonstrates electric-field modulation of anomalous and topological Hall effects in oxide bilayer thin films, highlighting the role of strong spin-orbit coupling in nonmagnetic layers for electrical control of spintronic phenomena.

Contribution

It shows that electric fields can modulate Hall effects in oxide heterostructures by utilizing strong SOC in nonmagnetic layers, a breakthrough in controlling spintronic properties.

Findings

Electric field modulates Hall effects in oxide heterostructures.

Insertion of SrIrO3 enables electric-field control.

Strong SOC in SrIrO3 is key for tuning phenomena.

Abstract

One of the key technologies in spintronics is to tame spin-orbit coupling (SOC) that links spin and motion of electrons, giving rise to intriguing magneto-transport properties in itinerant magnets. Prominent examples of such SOC-based phenomena are anomalous and topological Hall effects. However, controlling them by electric field has remained unachieved since electric field tends to be screened in itinerant magnets. Here we demonstrate that both anomalous and topological Hall effects can be modulated by electric field in oxide heterostructures consisting of ferromagnetic SrRuO$_{3}$ and nonmagnetic SrIrO$_{3}$. We observed clear electric-field effect only when SrIrO$_{3}$ is inserted between SrRuO$_{3}$ and a gate dielectric. Our results establish that strong SOC of nonmagnetic materials such as SrIrO$_{3}$ is essential in electrical tuning of these Hall effects and possibly other SOC-related phenomena.