Electrical manipulation of a Weyl semimetallic state

Electrical manipulation of emergent phenomena due to nontrivial band topology is a key to realize next-generation technology using topological protection. Recent discovery of the magnetic Weyl fermions in the antiferromagnet Mn₃Sn has attracted significant attention [1], as it exhibits various exotic phenomena with robust properties due to the Weyl nodes [2-6]. Given the prospects of antiferromagnetic (AF) spintronics for realizing high-density devices with ultrafast operation, it would be ideal if one could electrically manipulate an AF Weyl semimetal. Here we demonstrate the electrical switching of a Weyl semimetal state and its detection by anomalous Hall effect (AHE) [7]. In particular, we employ a polycrystalline thin film of the AF Weyl metal Mn₃Sn. Using the bilayer device of Mn₃Sn and nonmagnetic metals (NMs), we find that an electrical current density of ~10¹⁰-10¹¹ A/m² in NMs induces the magnetic switching with a large change in Hall voltage, and besides, the current polarity along a bias field and the sign of the spin Hall angle of NMs determines the sign of the Hall voltage. Notably, the electrical switching in the antiferromagnet is made using the same protocol as the one used for ferromagnetic metals. Our observation may well lead to another leap in science and technology for topological magnetism and AF spintronics. This is the work in collaboration with H. Tsai, T. Higo, K. Kondou, T. Nomoto, A. Sakai, A. Kobayashi, T. Nakano, K. Yakushiji, T. Koretsune, M. Suzuki, R. Arita, S. Miwa, Y. Otani, C. Broholm, P. Armitage, H. Chen, A. MacDonald.

[1] K. Kuroda, T. Tomita et al., Nat. Mater. 16, 1090-1095 (2017).
[2] S. Nakatsuji, N. Kiyohara, T. Higo, Nature 527, 212-215 (2015).
[3] M. Ikhlas, T. Tomita et al., Nat. Phys. 13, 1085-1090 (2017).
[4] T. Higo et al., Nat. Photon. 12, 73-78 (2018).
[5] T. Matsuda et al., Nat. Comm. 11, 2863 (2020).
[6] M. Kimata et al., Nature 565, 627–630 (2019).
[7] H. Tsai, T. Higo et al., Nature 580, 608–613(2020).