Metallic antiferromagnets with broken inversion symmetry on the two sublattices, strong spin-orbit coupling and high N\'{ e}el temperatures offer new opportunities for applications in spintronics. Especially Mn$_{ 2}$Au, with high N\'{ e}el temperature and conductivity, is particularly interesting for real-world applications. Here, manipulation of the orientation of the staggered magnetization,\textit{ \ i.e.} the N\'{ e}el vector, by current pulses has been recently demonstrated, with the read-out limited to studies of anisotropic magnetoresistance or X-ray magnetic linear dichroism. Here, we report on the in-plane reflectivity anisotropy of Mn$_{ 2}$Au (001) films, which were N\'{ e}el vector aligned in pulsed magnetic fields. In the near-infrared, the anisotropy is $\approx$ 0.6\%, with higher reflectivity for the light polarized along the N\'{ e}el vector. The observed magnetic linear dichroism is about four times larger than the anisotropic magnetoresistance. This suggests the dichroism in Mn$_{ 2}$Au is a result of the strong spin-orbit interactions giving rise to anisotropy of interband optical transitions, in-line with recent studies of electronic band-structure. The considerable magnetic linear dichroism in the near-infrared could be used for ultrafast optical read-out of the N\'{ e}el vector in Mn$_{ 2}$Au.
Categories: cond-mat.mtrl-sci cond-mat.mes-hall
