Observation of Large Topologically Trivial Fermi-Arcs in the Candidate Type-II Weyl Semimetal WTe2

TL;DR

This study uses photoemission experiments and calculations to show that the observed Fermi arcs in WTe2 are topologically trivial, challenging their use as indicators of Weyl semimetal behavior.

Contribution

The paper demonstrates that Fermi arcs in WTe2 are topologically trivial and independent of Weyl points, providing new insights into surface states in topological materials.

Findings

Fermi arcs in WTe2 are topologically trivial.

Surface states are independent of bulk Weyl points.

Clarified the number of Fermi surface sheets in WTe2.

Abstract

We report angle-resolved photoemission experiments resolving the distinct electronic structure of the inequivalent top and bottom (001) surfaces of WTe2. On both surfaces, we identify a surface state that forms a large Fermi-arc emerging out of the bulk electron pocket. Using surface electronic structure calculations, we show that these Fermi arcs are topologically trivial and that their existence is independent of the presence of type-II Weyl points in the bulk band structure. This implies that the observation of surface Fermi arcs alone does not allow the identification of WTe2 as a topological Weyl semimetal. We further use the identification of the two different surfaces to clarify the number of Fermi surface sheets in WTe2.