2025/09/26 by Tanaka, Katsuhiro, Toga, Yuta, Minami, Susumu +4
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2509.21877
The antiferromagnets with the time-reversal symmetry broken magnetic structures possess a finite spin splitting in the momentum space, and may contribute to a realization of a finite tunnel magnetoresistance (TMR) effect even with magnets with zero net spin polarization. In this paper, we study the TMR effect with the noncollinear antiferromagnet \mathrmMn3Sn whose inverse 120∘ antiferromagnetic order breaks the time-reversal symmetry. In particular, we employ the representative barrier material MgO as the tunnel insulator, and calculate the TMR effect in the \mathrmMn3Sn(0110)/MgO(110)/\mathrmMn3Sn magnetic tunnel junctions (MTJs), which has an optimal geometry for the spin-orbit torque switching of the magnetic configurations. We show that a finite TMR ratio reaching \gtrsim 1000% appears in the \mathrmMn3Sn/MgO/\mathrmMn3Sn MTJs, which is due to the spin splitting properties of \mathrmMn3Sn in the momentum space combined with the screening effect of MgO.