Tunable magnetization relaxation in spin valves
  In spin values the damping parameters of the free layer are determined non-locally by the entire magnetic configuration. In a dual spin valve structure that comprises a free layer embedded between two pinned layers, the spin pumping mechanism, in combination with the angular momentum conservation, renders the tensor-like damping parameters tunable by varying the interfacial and diffusive properties. Simulations based on the Landau-Lifshitz-Gilbert phenomenology for a macrospin model are performed with the tensor-like damping and the relaxation time of the free layer magnetization is found to be largely dependent on while tunable through the magnetic configuration of the source-drain magnetization. 
Xuhui Wang and Aurelien Manchon
cond-mat.mes-hall