Observation of the Spin-Injection Terahertz Emission in Planar Ferromagnetic Two-Layer Structures

The spin-injection emission of the system that consists of a nonmagnetic conducting rod and two-layer planar heteroepitaxial structure formed by thin metal and magnetite films is experimentally studied. The electromagnetic emission in the terahertz range is demonstrated for the first time due to the creation of the nonequilibrium population of the spin energy subbands (relatively low current densities of about 10(5) A/cm(2) are needed at room temperature).