The 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/k², 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. 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 clean limit. This implies the emergence of a gigantic contribution to the non-linear Hall effect in such devices.