Te 5porbitals bring three-dimensional electronic structure to two-dimensional Ir0.95Pt0.05Te2

Abstract

We have studied the nature of the three-dimensional multiband electronic structure in the two-dimensional triangular lattice Ir${}_{1\ensuremath{-}x}$Pt${}_{x}$Te${}_{2}$ ($x=0.05$) superconductor using angle-resolved photoemission spectroscopy (ARPES), x-ray photoemission spectroscopy (XPS), and a band structure calculation. ARPES results clearly show a cylindrical (almost two-dimensional) Fermi surface around the zone center. Near the zone boundary, the cylindrical Fermi surface is truncated into several pieces in a complicated manner with strong three dimensionality. The XPS result and the band structure calculation indicate that the strong Te 5$p$-Te 5$p$ hybridization between the IrTe${}_{2}$ triangular lattice layers is responsible for the three dimensionality of the Fermi surfaces and the intervening of the Fermi surfaces observed by ARPES.