Non-equilibrium spin waves in paramagnetic metals
A.F. Ioffe Physico-Technical Institute of Russian Academy of Sciences - 194021 St. Petersburg, Russia
Accepted: 14 June 2010
We theoretically study the effect of exchange interaction on the non-equilibrium spin waves in disordered paramagnetic metals under the spin injection condition. We show that the gapless spectrum of spin waves, describing the spin precession in the absence of the applied magnetic field, changes sign to negative on the paramagnetic side near the ferromagnet-paramagnet phase transition. The damping of spin waves is small in the limit when electron-electron exchange energy is larger than the inverse electron mean free time, while in the opposite limit the propagation of spin waves is strongly suppressed. We discuss the amplification of the electromagnetic field by the non-equilibrium spin waves.
PACS: 75.30.Ds – Spin waves / 71.27.+a – Strongly correlated electron systems; heavy fermions / 72.25.Hg – Electrical injection of spin-polarized carriers
© EPLA, 2010