Spin-injection generators of terahertz waves based on metal magnetic structures

Fundamentally new devices for the generation of terahertz waves due to the effect of the spin-polarized current in ferromagnetic and antiferromagnetic metal structures (magnetic junctions) are considered. The spin injection and the sd exchange and its effect on the interaction with electromagnetic waves play the main role in such devices. The effects that are induced by the polarized current in the antiferromagnetic materials (exchange instability, induced magnetization, and spin-injection antiferromagnetic resonance) are discussed. The principles and effects of the generation of the terahertz electromagnetic oscillations are considered, and the characteristics of the experimental prototypes of the corresponding devices are analyzed.