Macrospin model of incubation delay due to the field-like spin transfer torque

TL;DR

This paper explains the incubation delay in magnetic tunnel junctions using a macrospin model that incorporates a significant field-like spin-transfer torque component, and proposes a method to measure its voltage dependence.

Contribution

It introduces a macrospin model accounting for field-like torque to explain incubation delay and suggests a measurement approach for its voltage dependence.

Findings

Absence of pre-switching oscillations explained by field-like torque

Proposed measurement method for voltage dependence of torque

Macrospin model aligns with experimental observations

Abstract

We show that the absence of pre-switching oscillations ("incubation delay") in magnetic tunnel junctions can be explained within the macrospin model by a sizable field-like component of the spin-transfer torque. It is further suggested that measurements of the voltage dependence of tunnel junction switching time in the presence of external easy axis magnetic fields can be used to determine the magnitude and voltage dependence of the field-like torque.