  As they do not rely on the presence of any crystal symmetry, Weyl nodes are
robust topological features of an electronic structure that can occur at any
momentum and energy. Acting as sinks and sources of Berry curvature, Weyl nodes
have been predicted to strongly affect the transverse electronic response, like
in the anomalous Hall or Nernst effects. However, to observe large anomalous
effects the Weyl nodes need to be close to or at the Fermi-level, which implies
the band structure must be tuned by an external parameter, e.g. chemical doping
or pressure. Here we show that in a ferromagnetic metal tuning of the Weyl node
energy and momentum can be achieved by rotation of the magnetization. Taking
Co$_3$Sn$_2$S$_2$ as an example, we use electronic structure calculations based
on density-functional theory to show that not only new Weyl fermions can be
created by canting the magnetization away from the easy axis, but also that the
Weyl nodes can be driven exactly to the Fermi surface. We also show that the
dynamics in energy and momentum of the Weyl nodes strongly affect the
calculated anomalous Hall and Nernst conductivities.
