Observation of current-driven fast magnetic domain-wall motion in noncollinear antiferromagnets

Antiferromagnets have the natural advantages of ultrafast magnetization dynamics and negligible stray fields compared with ferromagnets, thus appealing for next-generation spintronics devices with ultrafast operations. However, even the fundamental study of the magnetization dynamics in antiferromagnets has been challenging because of their insensitive magneto-electric responses. Recently, remarkable progress has been reported that antiferromagnets enabled us to detect and manipulate their antiferromagnetic domain states by utilizing the noncollinear spin structure in Mn3X (X = Sn, Ge) [1-7].

Here, we focused on current-driven magnetic domain wall motion which is one of the crucial topics in the spintronics field. Then, we show a first observation of current-driven fast domain-wall motion with a low current density in single crystal Mn3X wires [8]. It implies extremely high mobility compared with typical ferromagnets, an important character for ultrafast operation devices. Interestingly we found the strong dependence of domain wall structure for the propagation speed. We theoretically extended the spin-torque phenomenology for domain-wall dynamics from collinear to noncollinear magnetic systems to understand such novel current-induced spin dynamics. These findings open a new route to developing a mechanism for antiferromagnetic domain-wall-based applications.

References

[1] S. Nakatsuji et al., Nature 527, 212–215 (2015).

[2] T. Higo, et al., Nat. Photon. 12, 73–78 (2018).

[3] H. Tsai, et al., Nature 580, 608–613 (2020).

[4] Y. Takeuchi et al., Nat. Mater. 20, 1364–1370 (2021).

[5] T. Higo, et al., Nature 607, 474–479 (2022).

[6] B. Pal et al., Sci. Adv. 8, 24 (2022).

[7] J-Y. Yoon et al., Nat. Mater. 22, 1106–1113 (2023).

[8] M. Wu Nat. Commun. 15, 4305 (2024).