Optical Readout of the Néel Vector in the Metallic Antiferromagnet Mn 2 Au

Metallic antiferromagnets with broken inversion symmetry on the two sublattices, strong spin-orbit cou- pling, and high Neel temperatures offer alternative opportunities for applications in spintronics. Especially Mn2Au, with a high Neel temperature and high conductivity, is particularly interesting for real-world applications. Here, manipulation of the orientation of the staggered magnetization, (i.e., the Neel vector) by current pulses was recently demonstrated, with the readout limited to studies of anisotropic magne- toresistance or x-ray magnetic linear dichroism. Here we report on the in-plane reflectivity anisotropy of Mn2Au(001) films, which are Neel vector aligned in pulsed magnetic fields. In the near-infrared region, the anisotropy is approximately 0.6%, with higher reflectivity for the light polarized along the Neel vector. The observed magnetic linear dichroism is about 4 times larger than the anisotropic magnetoresistance. This suggests the dichroism in Mn2Au is a result of the strong spin-orbit interactions giving rise to anisotropy of interband optical transitions, which is in line with recent studies of electronic band structure. The con- siderable magnetic linear dichroism in the near-infrared region could be used for ultrafast optical readout of the Neel vector in Mn2Au.