Noncollinear ferromagnetic Weyl semimetal with anisotropic anomalous Hall effect

Abstract

The connection of novel electromagnetic responses to Weyl nodes in topological semimetals is intriguing but difficult to establish in experiments. Here, the authors discover CeAlSi to be a new ferromagnetic Weyl semimetal by combining first-principles calculations with various experimental techniques. These reveal a new loop Hall effect that is induced purely by the proximity of the material's Fermi level to its Weyl nodes. The loop Hall effect can potentially result from topological Fermi arcs located on magnetic domain walls.