Prediction of Tunneling Magnetoresistance and Spin-Transfer Torque Effects in Antiferromagnetic Tunnel Junctions

A magnetic tunnel junction (MTJ) is a conventional spintronic device exploiting tunneling magnetoresistance (TMR) to read-out and spin-transfer torque (STT) to write-in the information that is stored in magnetization of ferromagnetic layers. With the advantages of antiferromagnets being robust against magnetic perturbations, producing no stray fields, and exhibiting ultrafast dynamics, it would be desirable to realize an antiferromagnetic (AFM) tunnel junction (AFMTJ)—an MTJ analog for AFM spintronics. Here, we predict that large TMR and STT effects with the strengths comparable to these in commercial MTJs can be observed in RuO
2
/TiO
2
/RuO
2
AFMTJs. We argue that both phenomena can be interpreted in terms of the Néel spin currents, i.e., staggered spin currents flowing through different magnetic sublattices, which effectively transfer current carrying spins between the RuO
2
AFM electrodes across the TiO
2
barrier. Our work uncovers the unexplored potential of antiferromagnets for the efficient writing and reading of information in AFM spintronics.