Temperature dependence of the anisotropic magnetoresistance of the metallic antiferromagnet Fe 2 As

Electrical readout of metallic antiferromagnet (AFM) memories is typically realized by measuring the anisotropic magnetoresistance (AMR), but the mechanisms for enhanced AMR are not yet established. We study AMR of single crystals of AFM ${\mathrm{Fe}}_{2}\mathrm{As}$ from $T=5$ K to above the N\'eel temperature, ${T}_{N}\ensuremath{\approx}353$ K. With an applied magnetic field $B$ rotating in the (001) plane, we observe a peak-to-peak AMR change of 1.3% for $Bg1$ T at $T=5$ K, one order of magnitude larger than reported in $\mathrm{Cu}\mathrm{Mn}\mathrm{As}$, a widely studied candidate for AFM spintronics. The AMR varies strongly with temperature, decreasing by a factor of approximately 10 at $T\ensuremath{\approx}200$ K. Our results suggest that large AMR in easy-plane AFMs may require N\'eel temperatures that greatly exceed room temperature.