A magnon spin-orbit coupling, induced by the dipole-dipole interaction, is derived in monoclinic-stacked bilayer honeycomb spin lattice with perpendicular magnetic anisotropy and antiferromagnetic interlayer coupling. Linear crossings are predicted in the magnon spectrum around the band minimum in G valley, as well as in the high frequency range around the zone boundary. The linear crossings in K and K' valleys, which connect the acoustic and optical bands, can be gapped when the intralayer dipole-dipole or Kitaev interactions exceed the interlayer dipole-dipole interaction, resulting in a phase transition from semimetal to insulator. Our results are useful for analyzing the magnon spin dynamics and transport properties in van der Waals antiferromagnet.
@article{arxiv.2009.13660,
title = {Spin-orbit coupling and linear crossings of dipolar magnons in van der Waals antiferromagnets},
author = {Jie Liu and Lin Wang and Ka Shen},
journal= {arXiv preprint arXiv:2009.13660},
year = {2020}
}