Voltage-induced terahertz magnon excitation associated with antiferromagnetic domain wall precession

Exploring a low-power method for exciting terahertz (THz) signals is of great interest in developing devices with ultrafast signal processing. We numerically investigated the THz magnon excitation from a moving antiferromagnetic (AFM) domain wall (DW) driven by a voltage-induced magnetic anisotropy energy gradient (dE(a)/dx). This magnon excitation originates from the DW precession induced by dE(a)/dx. Unlike the AFM DW precession triggered by DW acceleration as predicted in previous investigation, the dE(a)/dx-induced DW precession is possible when the DW acceleration is negligible. When the frequency of DW precession is greater than the frequency gap of spin-wave propagation in the AFM medium, THz magnons are resonantly excited. Because dE(a)/dx can be generated under a moderate DC voltage, our work provides a potential approach for developing THz spintronic devices with a low power and dissipation.

Automated summary

In this study, we numerically investigated THz magnon excitation from a moving antiferromagnetic domain wall driven by a voltage-induced magnetic anisotropy energy gradient. The resonant excitation of THz magnons was observed when the frequency of domain wall precession was higher than the frequency gap of spin-wave propagation in the medium. This work provides a potential approach for developing low-power THz spintronic devices.