Model for a collimated spin wave beam generated by a single layer, spin torque nanocontact

TL;DR

This paper presents a semi-classical model for spin torque-induced magnetization dynamics in a single-layer nanocontact, predicting controllable, collimated spin wave beams and complex wave structures influenced by Oersted fields and external magnetic orientation.

Contribution

It introduces a novel model incorporating Oersted effects to predict directional, coherent spin wave structures generated by a single-layer nanocontact.

Findings

Generation of collimated spin wave beams controllable by external fields

Prediction of vortex spiral and standing wave structures

Control of spin wave propagation via Oersted fields and field orientation

Abstract

A model of spin torque induced magnetization dynamics based upon semi-classical spin diffusion theory for a single layer nanocontact is presented. The model incorporates effects due to the current induced Oersted field and predicts the generation of a variety of spatially dependent, coherent, precessional magnetic wave structures. Directionally controllable collimated spin wave beams, vortex spiral waves, and localized standing waves are found to be excited by the interplay of the Oersted field and the orientation of an applied field. These fields act as a spin wave ``corral'' around the nanocontact that controls the propagation of spin waves in certain directions.