Electrical manipulation of non-collinear antiferromagnet

Shunsuke Fukami, Tohoku University

Electrical manipulation of magnetic materials has been of paramount interest in the spintronics research for the last quarter of a century, and many interesting phenomena have been revealed, offering various opportunities of applications. Non-collinear antiferromagnet with chiral-spin structure is an attractive system showing intriguing properties that had been believed to be inherent to ferromagnets, such as the anomalous Hall effect [1]. A recent study demonstrated an electrical switching of chiral-spin structure in the same protocol with magnetization switching in ferromagnets [2].
In this seminar, I will show a new phenomenon unique to the non-collinear antiferromagnet, i.e., chiral-spin rotation [3]. We use Hall-bar devices with an epitaxial stack consisting of non-collinear antiferromagnetic Mn3Sn and heavy metals with large spin-orbit coupling [4,5]. An unconventional response of the Hall resistance under current applications is observed, which can be attributed to the continuous rotation of chiral-spin structure in Mn3Sn driven by the spin-orbit torque. We also find that the efficiency to manipulate the magnetic structure through this scheme is much higher than that in collinear ferromagnets and ferrimagnets.

[1] S. Nakatsuji et al., Nature 527, 212 (2015).
[2] H. Tsai et al., Nature 580, 608 (2020).
[3] Y. Takeuchi et al., Nature Materials, advanced online publication (2021). https://doi.org/10.1038/s41563-021-01005-3.
[4] J.-Y. Yoon et al., Appl. Phys. Express, 13, 013001 (2019); J.-Y. Yoon et al. AIP Adv. 11, 065318 (2021).

PDF file of the talk available here