  We investigated spin Hall magnetoresistance in FeMn/Pt bilayers, which was
found to be one order of magnitude larger than that of heavy metal and
insulating ferromagnet or antiferromagnet bilayer systems, and comparable to
that of NiFe/Pt bilayers. The spin Hall magnetoresistance shows a non-monotonic
dependence on the thicknesses of both FeMn and Pt. The former can be accounted
for by the thickness dependence of net magnetization in FeMn thin films,
whereas the latter is mainly due to spin accumulation and diffusion in Pt.
Through analysis of the Pt thickness dependence, the spin Hall angle, spin
diffusion length of Pt and the real part of spin mixing conductance were
determined to be 0.2, 1.1 nm, and $5.5 * 10^{14} {\Omega}^{-1} m^{-2}$,
respectively. The results corroborate the spin orbit torque effect observed in
this system recently.
