Tunneling Magnetoresistance in Noncollinear Antiferromagnetic Tunnel Junctions

Antiferromagnetic spintronics has emerged as a subfield of spintronics driven by the advantages of antiferromagnets producing no stray fields and exhibiting ultrafast magnetization dynamics. The efficient method to detect an antiferromagnetic order parameter, known as the Néel vector, by electric means is critical to realize concepts of antiferromagnetic spintronics. Here, using fist-principles calculations, we predict a tunneling magnetoresistance effect as high as 100% in antiferromagnetic tunnel junctions with Mn 3 Sn electrodes which exhibit a momentum dependent spin polarization. Moreover, further studies demonstrate that in single-crystalline Mn 3 Pt/perovskite oxides/Mn 3 Pt antiferromagnetic tunnel junctions, tunneling magnetoresistance can reach over 800%. We argue that the spin-split band structure and the related tunneling magnetoresistance effect can also be realized in other noncollinear antiferromagnetic metals like Mn 3 Ge, Mn 3 Ga and Mn 3 GaN. Our work may provide a robust method for detecting the Néel vector in noncollinear antiferromagnets via the tunneling magnetoresistance effect, which should be useful for their application in antiferromagnetic spintronic devices.