Terahertz bremsstrahlung and frequency comb induced by variable motion of an antiferromagnetic domain wall. (21st July 2022)

• Record Type: Journal Article
• Authors: Ge, Xu; Chen, Yangyi; Cao, Yue; Li, Can; Li, Tailin; Li, Ziquan; You, Long; Liang, Shiheng; Yang, Xiaofei; Zhang, Yue
• Is Part Of: Journal of physics. Volume 55:Number 29(2022)
• Publication Date: 2022-07-21
• Subjects: bremsstrahlung spin wave -- frequency comb -- antiferromagnetic domain wall -- variable motion; Physics -- Periodicals; 530
• DOI: 10.1088/1361-6463/ac6a28
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: We numerically investigate the emission of spin wave (SW) packets from an antiferromagnetic (AFM) domain wall (DW) moving at a varying velocity. This SW is analogous to the bremsstrahlung of a charge with variable motion. The SW packets are emitted towards both sides of DW in the DW acceleration/deceleration process. The frequency of this bremsstrahlung-type SW is at sub-terahertz (THz), which is one magnitude lower than that of SW emitted by the Lorentz contraction of DW. Based on the bremsstrahlung-type SW, we proposed a frequency comb with a sub-THz central frequency and a GHz frequency interval by exploiting the back-and-forth DW variable motion. Our work paves a way for developing a spin–orbit-torque -based AFM THz device with a tunable frequency band.