Generation of THz-frequency electromagnetic signals in antiferromagnetic multilayered nanostructures biased by a spin current

摘要

There are several approaches to the THz-frequency generation, however the existing techniques require complex experimental setups and can not be realized even at micron-scale. In contradiction to this a thin antiferromagnetic nanostructure covered by a thin metal layer having the strong spin-orbital coupling and biased by a DC spin current can be used as nano-scale source of electromagnetic AC signals with frequencies close to the eigenfrequencies of the antiferromagnetic material (typically 0.1-10 THz). In this paper we theoretically analyze the efficiency of such a generator based on hematite and platinum layered nanostructures and estimate its output AC power. Our calculations show that the output AC power of the source could exceed several μW in the frequency range 1-3 THz, if the multilayered nanostructure is embedded in high-Q dielectric resonator.