Quasiparticle interference on type-I and type-II Weyl semimetal surfaces: a review

TL;DR

This review discusses quasiparticle interference experiments on type-I and type-II Weyl semimetal surfaces, highlighting their topological features, surface states, and potential future applications in topological materials research.

Contribution

It provides a comprehensive overview of quasiparticle interference findings on Weyl semimetals, emphasizing differences between type-I and type-II classes and their surface phenomena.

Findings

Topological sink effect of surface carriers

Weakly bound Fermi arc surface states

Orbital dependent scattering channels

Abstract

Weyl semimetals are a new member of the topological materials family, featuring a pair of singly degenerate Weyl cones with linear dispersion around the nodes in the bulk, and Fermi arcs on the surface. Depending on whether the system conserves or violates Lorentz symmetry, Weyl semimetals can be categorized into two classes. Photoemission spectroscopy measurements have confirmed the TaAs-class and WTe2-class of Weyl semimetals as type-I and type-II respectively. This review article aims to elucidate and elaborate on the basic concepts of Weyl semimetals and quasiparticle interference experiments on both type-I and type-II Weyl semimetals. The versatile results which reveal (1) the topological sink effect of the surface carriers, the unique feature of the Fermi arc state; (2) the weakly bound nature of the Fermi arc surface state; (3) the orbital dependent scattering channels on the surface; (4) a mirror symmetry protected surface Dirac cone, are summarily discussed. Finally, a perspective toward the future applications of quasiparticle interference techniques on topological materials is presented.