Surface State Bands in Superconducting (Pt_xIr_1-x)Te₂

Angle-resolved photoemission spectroscopy is performed to study the bulk and surface electronic structures of nonsuperconducting IrTe₂ and superconducting Pt_0.05Ir_0.95Te₂. In addition to the bulk electronic bands predicted by the local density approximation calculations, we observe two Dirac cone-like bands at the Brillouin zone center, which are non-dispersive along k_z, suggesting that the extra bands are surface state bands. As the experimental results are well consistent with the ab initio calculations of surface states, the parity analysis proves that these surface state bands are topologically trivial and thus exclude (Pt_xIr_1-x)Te₂ as a possible topological superconductor candidate.