Abstract:

I present theoretical results obtained in my group on ultrafast spin dynamics of holes and electrons in bulk GaAs. The spin-dependent carrier dynamics is computed by solving dynamical equations for the spin-density matrix containing Boltzmann-type scattering integrals, which include carrier-carrier Coulomb scattering, phonon scatterin, and impurity scattering. The influence of excitation conditions and doping on the spin dynamics and spin relaxation times is discussed. A comparison with experiments is also provided.
If time permits, I will also discuss a macroscopic description of spin transport through magnetic multilayers, which allows one to extract a well-defined signal propagation velocity for a modulated (or switched) spin current. Our approach shows that dynamical spin transport through magnetic multilayers possesses both diffusion and wave characteristics. The latter allow one to define the signal propagation velocity and lead to deviations from a diffusive behavior for high-frequency modulation.
 
 
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