Micromagnetic simulations of the magnetization precession induced by a spin polarized current in a point contact geometry

TL;DR

This paper uses micromagnetic simulations to study magnetization precession caused by spin-polarized currents in point contact geometries, highlighting methodological challenges and discrepancies with experimental results.

Contribution

It provides a detailed analysis of simulation methods and reveals limitations of the standard Slonczewski formalism in modeling spin-torque effects.

Findings

Standard formalism leads to qualitative disagreement with experiments

Methodological issues are critical in simulating spin-torque dynamics

Physical results highlight the need for improved modeling approaches

Abstract

This paper is devoted to numerical simulations of the magnetization dynamics driven by a spin-polarized current in extended ferromagnetic multilayers when a point-contact setup is used. We present (i) detailed analysis of methodological problems arising by such simulations and (ii) physical results obtained on a system similar to that studied in Rippard et al., Phys. Rev. Lett., v. 92, 027201 (2004). We demonstrate that the usage of a standard Slonczewski formalism for the phenomenological treatment of a spin-induced torque leads to a qualitative disagreement between simulation results and experimental observations and discuss possible reasons for this discrepancy.