Quasi-particle interferences of the Weyl semimetals TaAs and NbP

TL;DR

This paper theoretically investigates the quasi-particle interference patterns in Weyl semimetals TaAs and NbP, revealing unique signatures of Weyl nodes and Fermi arcs that can guide experimental STM studies.

Contribution

It provides the first systematic calculation of QPI patterns from Fermi arc surface states in Weyl semimetals, identifying interference signatures of Weyl nodes.

Findings

QPI exhibits termination points as fingerprints of Weyl nodes.

Proposes interference signatures of Fermi arcs for STM detection.

Results are relevant for understanding surface transport in Weyl semimetals.

Abstract

The recent discovery of the first Weyl semimetal in TaAs provides the first observation of a Weyl fermion in nature. Such a topological semimetal features a novel type of anomalous surface state, the Fermi arc, which connects a pair of Weyl nodes through the boundary of the crystal. Here, we present theoretical calculations of the quasi-particle interference (QPI) patterns that arise from the surface states including the topological Fermi arcs in the Weyl semimetals TaAs and NbP. Most importantly, we discover that the QPI exhibits termination-points that are fingerprints of the Weyl nodes in the interference pattern. Our results, for the first time, propose an interference signature of the topological Fermi arcs in TaAs, which provides important guidelines for STM measurements on this prototypical Weyl semimetal compound. The scattering channels presented here is relevant to transport phenomena on the surface of the TaAs class of Weyl semimetals. Our work is also the first systematic calculation of the quantum interferences from the Fermi arc surface states, which is in general useful for future STM studies on other Weyl semimetals.