A semiclassical approach to surface Fermi arcs in Weyl semimetals

TL;DR

This paper offers a semiclassical framework to understand the shape and formation of surface Fermi arcs in Weyl and Dirac semimetals, linking their morphology to velocity fields and Berry curvatures.

Contribution

It introduces a novel semiclassical approach to analyze surface Fermi arcs, connecting their structure to velocity and Berry curvature effects, and extends this to surface magnetoplasma phenomena.

Findings

Fermi arcs' spiral structure arises from non-parallel velocity and momentum.

Mapping velocity fields reveals Fermi arc morphology for single and double Weyl points.

Surface magnetoplasma effects involve drift motion, chiral magnetic effect, and Imbert-Fedorov shift.

Abstract

We present a semiclassical explanation for the morphology of the surface Fermi arcs of Weyl semimetals. Viewing the surface states as a two-dimensional Fermi gas subject to band bending and Berry curvatures, we show that it is the non-parallelism between the velocity and the momentum that gives rise to the spiral structure of Fermi arcs. We map out the Fermi arcs from the velocity field for a single Weyl point and a lattice with two Weyl points. We also investigate the surface magnetoplasma of Dirac semimetals in a magnetic field, and find that the drift motion, the chiral magnetic effect and the Imbert-Fedorov shift are all involved in the formation of surface Fermi arcs. Our work not only provides an insightful perspective on the surface Fermi arcs and a practical way to find the surface dispersion, but also paves the way for the study of other physical properties of the surface states of topological semimetals, such as transport properties and orbital magnetization, using semiclassical methods.