We theoretically investigate dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet/heavy metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin-waves in the terahertz frequency range. The interplay between spin orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals in antiferromagnets.
@article{arxiv.1604.01473,
title = {Antiferromagnetic domain wall motion driven by spin-orbit torques},
author = {Takayuki Shiino and Se-Hyeok Oh and Paul M. Haney and Seo-Won Lee and Gyungchoon Go and Byong-Guk Park and Kyung-Jin Lee},
journal= {arXiv preprint arXiv:1604.01473},
year = {2016}
}