Current-pulse-induced magnetic switching in standard and nonstandard spin-valves

TL;DR

This paper theoretically investigates how current pulses induce magnetization switching in symmetric and asymmetric spin valves, revealing the influence of pulse duration and torque interplay on switching behavior and phase diagrams.

Contribution

It introduces a theoretical analysis of current-pulse-induced switching in both standard and nonstandard spin valves, highlighting the distinct stability features and proposing a scheme for ultrafast switching.

Findings

Switching depends on pulse duration and torque interplay.

Standard spin valves stabilize one magnetic configuration.

Nonstandard spin valves have both configurations stable or unstable depending on current.

Abstract

Magnetization switching due to a current-pulse in symmetric and asymmetric spin valves is studied theoretically within the macrospin model. The switching process and the corresponding switching parameters are shown to depend significantly on the pulse duration and also on the interplay of the torques due to spin transfer and external magnetic field. This interplay leads to peculiar features in the corresponding phase diagram. These features in standard spin valves, where the spin transfer torque stabilizes one of the magnetic configurations (either parallel or antiparallel) and destabilizes the opposite one, differ from those in nonstandard (asymmetric) spin valves, where both collinear configurations are stable for one current orientation and unstable for the opposite one. Following this we propose a scheme of ultrafast current-induced switching in nonstandard spin valves, based on a sequence of two current pulses.