| Summary: | In the paper, spin waves in a ferromagnetic nanotube
of an elliptic cross-section in the presence of a spinpolarized
electric current are investigated. The linearized
Landau-Lifshitz equation in themagnetostatic approximation
is used, with the exchange interaction, the dipoledipolemagnetic
interaction, the anisotropy effects and the
dissipation effects taken into account; the influence of the
spin-polarized current is considered by the Slonczewski-
Berger term. After elimination of the magnetization density
perturbation, an equation for the magnetic potential
for the above-described spin excitations is obtained. From
this equation, a dispersion relation for spin waves in the
nanosystem described previously is obtained. Analysis of
the dispersion relation shows that the presence of the spinpolarized
current can strengthen or weaken the dissipation,
creating an “effective dissipation”; the effect is analogous
to the “effective dissipation” in a two-layer ferromagnetic
film in the presence of a spin-polarized current. Depending
on the direction and the density of the current the
spinwave can decay faster or slower than in the absence of
the current, transform into a self-sustained wave or grow
in amplitude, thus leading to a spin wave generation.
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