Theory of magnetodynamics induced by spin torque in perpendicularly magnetized thin films

A nonlinear model of spin-wave excitation using a point contact in a thin ferromagnetic film is introduced. Large-amplitude magnetic solitary waves are computed, which help explain recent spin-torque experiments. Numerical simulations of the fully nonlinear model predict excitation frequencies in ex...

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Bibliographic Details
Published inPhysical review letters Vol. 95; no. 26; p. 267206
Main Authors Hoefer, M A, Ablowitz, M J, Ilan, B, Pufall, M R, Silva, T J
Format Journal Article
LanguageEnglish
Published United States 31.12.2005
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Summary:A nonlinear model of spin-wave excitation using a point contact in a thin ferromagnetic film is introduced. Large-amplitude magnetic solitary waves are computed, which help explain recent spin-torque experiments. Numerical simulations of the fully nonlinear model predict excitation frequencies in excess of 0.2 THz for contact diameters smaller than 6 nm. Simulations also predict a saturation and redshift of the frequency at currents large enough to invert the magnetization under the point contact. The theory is approximated by a cubic complex Ginzburg-Landau type equation. The mode's nonlinear frequency shift is found by use of perturbation techniques, whose results agree with those of direct numerical simulations.
ISSN:0031-9007
DOI:10.1103/physrevlett.95.267206