Search for nonreciprocal magnons in MnPS3...

Recent articles have suggested that the quasi-two-dimensional antiferromagnet MnPS3 may have nonreciprocal magnons, whereby magnons in a Brillouin zone corner at +q have different energies than those at −q. The magnons along the Brillouin zone boundaries were measured using neutron three-axis spectrometry, paying careful attention to the resolution function, to determine whether such nonreciprocity was present. The data show that, within the resolution, there are no significant differences between the magnons in opposite Brillouin zone corners. The findings are combined with a recently published study of MnPS3 by neutron resonant spin-echo spectroscopy and discussed within the context of the theories for nonreciprocal magnons.