ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Magnon-electron interaction is enhanced in the vicinity of an interface between ferromagnetic and normal layers, in metallic thin films. When a dc current crosses this interface, stimulated emission of spin-waves is predicted to take place. Beyond a certain critical current density (similar, equals)107 A/cm2, a spontaneous precession of the magnetization is predicted to arise. This SWASER (Spin Wave Amplification by Stimulated Emission of Radiation) is the magnetic equivalent of the injection laser. In the earlier theories, the thickness of the precessing magnetic layer was assumed to be larger than the electron mean free path. We now treat the case of general value of that thickness L2x. The current-induced amplification rate of spin-waves is proportional to L2x in the limit L2x(similar, equals)0, and goes through a maximum for L2x(similar, equals)π/|k↑−k↓|. Here, k↑ and k↓ are the spin-up and spin-down Fermi wave numbers. At larger L2x, the amplification rate of spin-waves decreases towards zero. On that general decrease are superposed damped periodic variations of wavelength (similar, equals)2π/|k↑−k↓|. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.364902
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