Observation of the spin-injection terahertz emission in planar ferromagnetic two-layer structures

Abstract

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).

sd-Exchange electron spin resonance in a ferromagnetic metal

“…One of the promising directions is the use of spin injection in magnetic transitions [4][5][6][7] that results in the inverse population of spin energy subbands. Experimental results confirming the possibility of generating tera hertz radiation with the use of magnetic transitions were obtained [8,9]. These data stimulate interest in systems resonant in the terahertz range that can be used as receivers of terahertz radiation.…”

Microwave-induced direct spin-flip transitions in mesoscopic Pd/Co heterojunctions

“…For example Korenivski and coworkers showed non-specific emission of radiation from arrays of FePt/Cu point contacts using an integrating bolometric detector [10,14]. Similarly, Gulayev et al reported radiation from large contacts (>10 μm in diameter) between a ferromagnetic rod and a second ferromagnetic film [15][16][17] or an antiferromagnetic FeMn layer [18,19] observed in bolometric measurements using a Golay cell without intrinsic spectral resolution. Although they showed that the source of radiation is partially non-thermal [19][20][21][22], it is not demonstrably associated to the above named mechanism.…”