Electric currents carrying a net spin polarization are widely used in spintronics, whereas globally spin-neutral currents are expected to play no role in spin-dependent phenomena. Antiferromagnetic (AFM) materials usually support only spin-neutral currents, and hence are largely restricted in realistic spintronic applications, despite being robust against magnetic perturbations, not producing stray fields, and exhibiting ultrafast spin dynamics. Here we show, in contrast to this common expectation, spin-neutral currents in antiferromagnets can drive novel spin-dependent transport phenomena in antiferromagnetic tunnel junctions (AFMTJs), such as a tunneling magnetoresistance (TMR) and a tunneling anomalous Hall effect (TAHE) promising for accurate read-out, and a spin-transfer-torque (STT) crucial for efficient write-in. These phenomena are due to that the globally spin-neutral currents in antiferromagnets can host Néel spin currents, i.e. staggered spin currents flowing through different magnetic sublattices. Our works uncover the previously unexplored potentials of antiferromagnets and pave a new route to realize the efficient writing and reading of information for antiferromagnetic spintronics.

References:

[1] Ding-Fu Shao, et al., Spin-neutral currents for spintronics, Nat. Commun. 12, 7061 (2021).
[2] Ding-Fu Shao, et al., Spin-neutral tunneling anomalous Hall effect, Phys. Rev. B 106, L180404 (2022)
[3] Ding-Fu Shao, et al., Néel Spin Currents in Antiferromagnets, arXiv:2212.02367; Phys. Rev. Lett. (2023).