Berry curvature associated to Fermi arcs in continuum and lattice Weyl systems

TL;DR

This paper investigates the divergence of surface Berry curvature in Weyl semimetals, linking continuum and lattice models, and explores its impact on various transport phenomena including the non-linear Hall effect.

Contribution

It analytically demonstrates the divergence of surface Berry curvature in lattice Weyl semimetals and connects these findings to continuum models, highlighting effects on transport phenomena.

Findings

Surface Berry curvature diverges at Fermi arc ends as 1/k^2.

Finite slab calculations confirm size effects on Berry curvature.

Divergent Berry curvature influences non-linear Hall, Magnus-Hall, and chiral anomaly effects.

Abstract

Recently it has been discovered that in Weyl semimetals the surface state Berry curvature can diverge in certain regions of momentum. This occurs in a continuum description of tilted Weyl cones, which for a slab geometry results in the Berry curvature dipole associated to the surface Fermi arcs growing linearly with slab thickness. Here we investigate analytically incarnations of lattice Weyl semimetals and demonstrate this diverging surface Berry curvature by solving for their surface states and connect these to their continuum descriptions. We show how the shape of the Fermi arc and the Berry curvature hot-line is determined and confirm the 1/k^2 divergence of the Berry curvature at the end of the Fermi arc as well as the finite size effects for the Berry curvature and its dipole, using finite slab calculations and surface Green's function methods. We further establish that apart from affecting the second order, non-linear Hall effect, the divergent Berry curvature has a strong impact on other transport phenomena as the Magnus-Hall effect and the non-linear chiral anomaly.