Infinite Berry Curvature of Weyl Fermi Arcs

We show that Weyl Fermi arcs are generically accompanied by a divergence of the surface Berry curvature scaling as 1/k(2), where k is the distance to a hot line in the surface Brillouin zone that connects the projection of Weyl nodes with opposite chirality, but which is distinct from the Fermi arc itself. Such surface Berry curvature appears whenever the bulk Weyl dispersion has a velocity tilt toward the surface of interest. This divergence is reflected in a variety of Berry curvature mediated effects that are readily accessible experimentally and, in particular, leads to a surface Berry curvature dipole that grows linearly with the thickness of a slab of a Weyl semimetal material in the limit of the long lifetime of surface states. This implies the emergence of a gigantic contribution to the nonlinear Hall effect in such devices.

Automated summary

The study shows that Weyl Fermi arcs are generally accompanied by a divergence of the surface Berry curvature that scales as 1/k(2), relating to the distance to a hot line in the surface Brillouin zone connecting the projection of Weyl nodes with opposite chirality. The emergence of this surface Berry curvature is mainly determined by the velocity tilt of the bulk Weyl dispersion towards the surface of interest.