  A developing frontier in condensed matter physics is the emergence of novel
electromagnetic responses, such as topological and anomalous Hall effect (AHE),
in ferromagnetic Weyl semimetals (FM-WSMs). Candidates of FM-WSM are limited to
materials that preserve inversion symmetry and generate Weyl crossings by
breaking time-reversal symmetry. These materials share three common features: a
centrosymmetric lattice, a collinear FM ordering, and a large AHE observed when
the field is parallel to the magnetic easy-axis. Here, we present CeAlSi as a
new type of FM-WSM, where the Weyl nodes are stabilized by breaking inversion
symmetry, but their positions are tuned by breaking time-reversal symmetry.
Unlike the other FM-WSMs, CeAlSi has a noncentrosymmetric lattice, a
noncollinear FM ordering, and a novel AHE that is anisotropic between the easy-
and hard-axes. It also exhibits large FM domains that are promising for both
device applications and an interplay between the Weyl nodes and FM domain
walls.
