All-voltage control of Giant Magnetoresistance

TL;DR

This paper demonstrates a novel all-voltage method to switch magnetization directions in a spin valve using strain control, enabling nonvolatile, low-power giant magnetoresistance manipulation for spintronic devices.

Contribution

It introduces a new approach utilizing exchange-biased bilayers and ferromagnetic coupling to achieve all-voltage control of magnetization states in spin valves.

Findings

All-voltage controlled GMR is repeatable and nonvolatile.

Magnetizations switch between states via strain-induced rotation.

Simulation confirms opposite rotation directions of Co layers.

Abstract

The aim of voltage control of magnetism is to reduce the power consumption of spintronic devices. For a spin valve, the magnetization directions of two ferromagnetic layers determine the giant magnetoresistance magnitude. However, achieving all-voltage manipulation of the magnetization directions between parallel and antiparallel states is a significant challenge. Here, we demonstrate that by utilizing two exchange-biased Co/IrMn bilayers with opposite pinning directions and with ferromagnetic coupling through the Ruderman-Kittel-Kasuya-Yosida interaction between two Co layers, the magnetization directions of the two ferromagnetic layers of a spin valve can be switched between parallel and antiparallel states through allvoltage-induced strain control. The all-voltage controlled giant magnetoresistance is repeatable and nonvolatile. The rotation of magnetizations in the two Co layers under voltages, from antiparallel to parallel states, occurs in opposite directions as revealed through simulations utilizing the Landau-Lifshitz-Gilbert equation. This work can provide valuable reference for the development of low-power all-voltage-controlled spintronic devices.