Large voltage-induced modification of spin-orbit torques in Pt/Co/GdOx

TL;DR

This paper demonstrates that applying voltage can significantly modify spin-orbit torques in a Pt/Co/GdOx structure, enhancing their strength and reducing magnetic anisotropy, which could improve spintronic device performance.

Contribution

It introduces a method to control spin-orbit torques via voltage-driven oxygen migration, revealing a large, tunable effect on magnetic properties.

Findings

Voltage-induced oxidation enhances Slonczewski-like torque by up to tenfold.

Magnetic anisotropy energy barrier is reduced by approximately five times.

Magneto-ionic control offers a new way to optimize spintronic device efficiency.

Abstract

We report on large modifications of current-induced spin-orbit torques in a gated Pt/Co/Gd-oxide microstrip due to voltage-driven O$^{2-}$ migration. The Slonczewski-like and field-like torques are quantified using a low-frequency harmonic technique based on the polar magneto-optical Kerr effect. Voltage-induced oxidation of Co enhances the Slonczewski-like torque by as much as an order of magnitude, and simultaneously reduces the anisotropy energy barrier by a factor of ~5. Such magneto-ionic tuning of interfacial spin-orbit effects may significantly enhance the efficiency of magnetization switching and provide additional degrees of freedom in spintronic devices.