Observation of Fermi Arcs in Type-II Weyl Semimetal Candidate WTe2

TL;DR

This study uses advanced ARPES techniques to observe Fermi arcs in WTe2, providing experimental confirmation of its status as a type-II Weyl semimetal, thus supporting theoretical predictions.

Contribution

First experimental observation of Fermi arcs in WTe2 confirming its classification as a type-II Weyl semimetal.

Findings

Fermi arcs observed connecting electron and hole pockets

Confirmation of theoretical predictions for WTe2

Strong evidence for type-II Weyl semimetallic states

Abstract

We use ultrahigh resolution, tunable, vacuum ultraviolet laser angle-resolved photoemission spectroscopy (ARPES) to study the electronic properties of WTe$_2$, a material that was predicted to be a type-II Weyl semimetal. The Weyl fermion states in WTe2 were proposed to emerge at the crossing points of electron and hole pockets; and Fermi arcs connecting electron and hole pockets would be visible in the spectral function on (001) surface. Here we report the observation of such Fermi arcs in WTe2 confirming the theoretical predictions. This provides strong evidence for type-II Weyl semimetallic states in WTe2.