  We have studied the nature of the three-dimensional multi-band electronic
structure in the twodimensional triangular lattice Ir1-xPtxTe2 (x=0.05)
superconductor using angle-resolved photoemission spectroscopy (ARPES), x-ray
photoemission spectroscopy (XPS) and 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
5p-Te 5p hybridization between the IrTe2 triangular lattice layers is
responsible for the three-dimensionality of the Fermi surfaces and the
intervening of the Fermi surfaces observed by ARPES.
