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Publication Citation: Theory of Magnetodynamics Induced by Spin Torque in Perpendicularly Magnetized Thin Films

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Author(s): Mark Hoefer; Mark J. Ablowitz; Boaz Ilan; Matthew R. Pufall; Thomas J. Silva;
Title: Theory of Magnetodynamics Induced by Spin Torque in Perpendicularly Magnetized Thin Films
Published: December 31, 2005
Abstract: 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 preduct 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.
Citation: Physical Review Letters
Volume: 95
Issue: 267206
Pages: pp. 1 - 4
Keywords: Ginzburg-Landau equation;Landau-Lifshitz equation;magnetic thin film;nonlinear differential equation;perturbation solution;point contact;spin-momentum transfer
Research Areas: Electromagnetics
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