Magnon spin transport through antiferromagnetic NiO

Thus far, antiferromagnets (AFMs) played a passive role of pinning in giant magnetoresistance. AFMs hold promise of ultrafast and lossless AFM transport devices ^[1] when one is able to simultaneously generate and detect spin currents, while having control over the magnetic moment directions. AFMs have no stray fields so we made use of either the magnetic easy-plane character^[2] or an attached ferromagnet to manipulate its magnetic moments.
Electrical and thermal injection of magnon spins occurs by a charge current through Pt, creating an interface spin accumulation via the Spin Hall Effect (SHE) and a thermally based magnon gradient. Resulting spin currents are detected by the inverse SHE, showing a 90° and 180° shift in the electrical and thermal signal respectively. Moreover, magnons that are detected non-locally revealed that both injection and detection is dependent on the magnetic texture of the NiO layer.

[1] Jungwirth et al., NNANO 11, 231
[2] Hoogeboom et al., APL 111, 052409