Spin-transfer pulse switching: From the dynamic to the thermally activated regime

TL;DR

This paper investigates how thermal fluctuations influence spin-transfer switching in nanomagnets across different time scales, identifying regimes dominated by thermal activation and spin angular momentum.

Contribution

It provides a comprehensive analysis of spin-transfer switching behavior over a wide range of time scales, bridging the dynamic and thermally activated regimes.

Findings

Distinguished long pulse thermal activation regime

Identified short pulse spin angular momentum regime

Quantified switching probabilities under various conditions

Abstract

The effect of thermal fluctuations on spin-transfer switching has been studied for a broad range of time scales (sub-ns to seconds) in a model system, a uniaxial thin film nanomagnet. The nanomagnet is incorporated into a spin-valve nanopillar, which is subject to spin-polarized current pulses of variable amplitude and duration. Two physical regimes are clearly distinguished: a long pulse duration regime, in which reversal occurs by spin-transfer assisted thermal activation over an energy barrier, and a short time large pulse amplitude regime, in which the switching probability is determined by the spin angular momentum in the current pulse.