TaIrTe4 a ternary Type-II Weyl semi-metal

TL;DR

This paper identifies TaIrTe4 as a new type-II Weyl semi-metal with only four Weyl points and extensive Fermi arcs, making it promising for experimental detection and study of topological surface states.

Contribution

It reports TaIrTe4 as a novel type-II Weyl semi-metal with minimal Weyl points and large Fermi arcs, expanding the family of known topological semi-metals.

Findings

TaIrTe4 hosts only four Weyl points, the minimum allowed by symmetry.

Fermi arcs extend over about one-third of the surface Brillouin zone.

Large momentum-space separation facilitates experimental detection.

Abstract

In metallic condensed matter systems two different types of Weyl fermions can in principle emerge, with either a vanishing (type-I) or with a finite (type-II) density of states at the Weyl node energy. So far only WTe2 and MoTe2 were predicted to be type-II Weyl semi-metals. Here we identify TaIrTe4 as a third member of this family of topological semi-metals. TaIrTe4 has the attractive feature that it hosts only four well-separated Weyl points, the minimum imposed by symmetry. Moreover, the resulting topological surface states - Fermi arcs connecting Weyl nodes of opposite chirality - extend to about 1/3 of the surface Brillouin zone. This large momentum-space separation is very favorable for detecting the Fermi arcs spectroscopically and in transport experiments.