Observation of Fermi Arcs in non-CentrosymmetricWeyl Semi-metal Candidate NbP

We report the surface electronic structure of niobium phosphide NbP single crystal on (001) surface by vacuum ultraviolet angle-resolved photoemission spectroscopy. Combining with our first principle calculations, we identify the existence of the Fermi arcs originated from topological surface states. Furthermore, the surface states exhibit circular dichroism pattern, which may correlated with spin texture. Our results not only provide critical evidence for the existence of the Weyl Fermions in NbP, but also lay foundations for further investigations.