Novel electromagnetic responses are expected in magnetic Weyl semimetals. However, the Weyl nodes in real materials are away from the Fermi level. This work reveals the presence of Weyl nodes at the Fermi level in CeAlSi from a combined analysis of density functional theory and quantum oscillations. Thus, a hitherto unobserved loop shape Hall effect in CeAlSi is interpreted as a purely topological effect. The loop Hall effect is a signature of topological Fermi arcs on the magnetic domain walls.
This work has been led by our PhD student, Hung-Yu Yang, who has just graduated from the Tafti Lab and started a postdoc position in Prof. Kang Wang’s lab at UCLA. Congratulations Hung-Yu!
