Magnetoresistance Effects in the Metallic Antiferromagnet Mn2Au

In antiferromagnetic spintronics, it is essential to separate the resistance modifications of purely magnetic origin from other effects generated by current pulses intended to switch the Neel vector. We investigate the magnetoresistance effects resulting from magnetic-field-induced reorientations of the staggered magnetization of epitaxial antiferromagnetic Mn2Au(001) thin films. The samples are exposed to 60-T magnetic field pulses along different crystallographic in-plane directions of Mn2Au(001), while their resistance is measured. For the staggered magnetization aligned via a spin-flop transition parallel to the easy [110] direction, an anisotropic magnetoresistance of similar or equal to -0.15% is measured. In the case of a forced alignment of the staggered magnetization parallel to the hard [100] direction, evidence for a larger anisotropic magnetoresistance effect is found. Furthermore, transient resistance reductions of similar or equal to 1% are observed, which we associate with the annihilation of antiferromagnetic domain walls by the magnetic field pulses.