Magnetization switching and spin oscillation dynamics in non-collinear antiferromagnets

Antiferromagnets (AFs) are promising candidates for next-generation spintronic devices, because of distinct benefits, such as fast magnetization dynamics and reduced crosstalk from magnetostatic interactions [1]. Towards this end, non-collinear AFs are particularly interesting for AF spintronics, since they exhibit a large anomalous Hall effect which can be used for detecting the magnetic order [2], which furthermore can be modulated electrically by the spin-orbit torques [3]. However, the detailed spin dynamics in the non-collinear AFs have not been satisfactorily explored. Here, we theoretically investigate spin dynamics in the non-collinear AFs, Mn3Sn. We prepare a minimal atomistic-spin model on a two-dimensional kagome lattice. From the model, we numerically calculate the switching dynamics among six degenerate stable configurations and compute AF resonance oscillations and the frequency. From the result, we find that different responses can be expected from in-plane and out-of-plane measurements, because of phase differences among the spin precessions. This work provides further insights required for non-collinear AF spintronics.

[1] T. Jungwirth, et al., Nat. Nanotech. 11, 231 (2016).

[2] S. Nakatsuji et al., Nature 527, 212 (2015).

[3] H. Tsai et al., Nature 580, 608 (2020).