Spin–orbit torque characterization in a nutshell

Abstract

Spin current and spin torque generation through the spin-orbit interactions in solids, of bulk or interfacial origin, are at the heart of spintronics research. The realization of spin-orbit torque (SOT) driven magnetic dynamics and switching in diverse magnetic heterostructures also paves the way for developing SOT magnetoresistive random access memory (SOT-MRAM) and other novel SOT memory and logic devices. Of scientific and technological importance are accurate and efficient SOT quantification techniques which have been abundantly developed in the last decade. In this article, we summarize popular techniques to experimentally quantify SOTs in magnetic heterostructures at micro-as well as nano-scale. For each technique, we give an overview of its principle, variations, strengths, shortcomings, error sources and any cautions in usage. Finally, we discuss the remaining challenges in understanding and quantifying the SOTs in heterostructures.I.

Spin-orbit torque switching of magnetic tunnel junctions for memory applications

“…There are several methods to experimentally characterize spin-orbit efficiencies 𝜉 , , a resume of them can found in Refs. [2,65].…”

Numerical Model Of Harmonic Hall Voltage Detection For Spintronic Devices

“…We adapt the standard Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation, like presented in, e.g., Nguyen et. al [21], into LL-form [6], such that it may be implemented in the numerical engine. The LLGS equation itself is given in the form where m = M µ 0 M s is the normalised magnetisation vector with µ 0 M s as the magnetisation saturation, α G is the dimensionless Gilbert damping parameter, H eff is the effective field vector, p is the polarisation vector, and γ 0 is the gyromagnetic factor.…”

“…In the experimental setup, we are primarily interested in measuring the effective torque efficiencies (ξ ), both the DL and FL. Those efficiencies may be easily calculated given the values of H DL , and H FL fields at a current density j e [21]:…”

A comprehensive simulation package for analysis of multilayer spintronic devices

“…The pivotal equation of the magnetic macrospin simulations is called Landau-Lifshitz-Gilbert-Slonczewski (LLGS) and takes the following form [13,[19][20][21][22]:…”