Strain-induced Megahertz Oscillation and Stable Velocity of an Antiferromagnetic Domain Wall

Manipulation of magnetic domain walls (DWs) in an antiferromagnet plays a fundamental role in developing antiferromagnetic (AFM) devices with small size and high velocity for information processing. On the other hand, in addition to the ultrahigh-frequency (THz) AFM magnetization precession, recent investigation shows that an antiferromagnet may also exhibit unique dynamical behaviors at a lower frequency (GHz) by an optical method. In this work, we predict the characteristic frequency of AFM magnetization dynamics can be further widened to MHz by triggering the oscillation of an AFM DW under a stress that is a sinusoidal function in a spatial coordinate. This low frequency is due to the mismatch of size between the spatial period of stress and DW width. Based on this low-frequency oscillation, DW can move at an almost constant velocity by shifting the phase of stress. The proposition in this work paves the way to develop AFM devices with small size and ultralow dissipation.