Spin Impedance and THz Radiation in Magnetic Junctions of Nanowires

An equivalent circuit scheme with lumped parameters for a magnetic junction formed in an array of two-layer nanowires is considered. In this scheme, the flow of electrons with relaxing spins is represented by a relaxation current flowing through an imaginary resistance. The possibility of a spin impedance arising at the interface between the layers, due to the inertia of the spin relaxation process, is shown in terms of the equivalent circuit. The non-thermal nature of the radiation observed during spin injection by current and the possible manifestation of spin impedance, when the radiation power increases with decreasing current, have been experimentally shown.