Criteria For Directly Detecting Topological Fermi Arcs In Weyl Semimetals

Abstract

The recent discovery of the first Weyl semimetal in TaAs provides the first observation of a Weyl fermion in nature and demonstrates a novel type of anomalous surface state, the Fermi arc. Like topological insulators, the bulk topological invariants of a Weyl semimetal are uniquely fixed by the surface states of a bulk sample. Here we present a set of distinct conditions, accessible by angle-resolved photoemission spectroscopy (ARPES), each of which demonstrates topological Fermi arcs in a surface state band structure, with minimal reliance on calculation. We apply these results to TaAs and NbP. For the first time, we rigorously demonstrate a nonzero Chern number in TaAs by counting chiral edge modes on a closed loop. We further show that it is unreasonable to directly observe Fermi arcs in NbP by ARPES within available experimental resolution and spectral linewidth. Our results are general and apply to any new material to demonstrate a Weyl semimetal.

Publication Date

2-10-2016

Publication Title

Physical Review Letters

Volume

116

Issue

6

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1103/PhysRevLett.116.066802

Socpus ID

84958190951 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84958190951

This document is currently not available here.

Share

COinS