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

Understand

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.