Current-induced four-state magnetization switching by spin-orbit torques in perpendicular ferromagnetic trilayers

TL;DR

This paper demonstrates a novel four-state magnetization switching in a trilayer system using spin-orbit torques, enabling multi-state memory with potential for low power and high density applications.

Contribution

It introduces a four-state magnetic memory device utilizing opposite spin currents in a trilayer system with different perpendicular magnetic anisotropies.

Findings

Achieved four distinct magnetic states via current pulses.

Demonstrated control of magnetization switching with different critical currents.

Proposed a new design for low power, high density spintronic devices.

Abstract

We demonstrated current-induced four-state magnetization switching in a trilayer system using spin-orbit torques. The memory device contains two Co layers with different perpendicular magnetic anisotropy, separated by a space layer of Pt. Making use of the opposite spin current at the top and bottom surface of the middle Pt layer, magnetization of both Co layers can be switched oppositely by the spin-orbit torques with different critical switching currents. By changing the current pulse forms through the device, the four magnetic states memory was demonstrated. Our device provides a new idea for the design of low power and high density spin-orbit torque devices.