Antiferromagnet-controlled spin current transport inSrMnO3/Pthybrids

We investigate the spin Hall magnetoresistance (SMR) in $\mathrm{SrMn}{\mathrm{O}}_{3}\phantom{\rule{0.16em}{0ex}}(\mathrm{SMO})/\mathrm{Pt}$ hybrids, where SMO is an antiferromagnetic (AFM) insulator. The AFM moments partially rotate with out-of-plane magnetic fields, producing room-temperature SMR. By manipulating the electron spins in Pt, we observe Larmor precession-induced oscillating SMR, reaffirming the spin current transport determined by the relative arrangement between the Pt electron spins and AFM moments. The use of the AFM with no net moments annihilates the magnetic proximity effect and thus confirms the SMR origination from AFM-controlled spin current transport, with significant spin mixing conductance of $\ensuremath{\sim}{10}^{17}\phantom{\rule{0.28em}{0ex}}{\mathrm{m}}^{\ensuremath{-}2}$. Our findings provide an interesting perspective to detecting AFM moments and represent a significant step towards AFM spintroincs.