title: Origin of first-order-type electronic and structural transitions in IrTe2.
abstract: We have explored the origin of unusual first-order-type electronic and structural transitions in IrTe2, based on the first-principles total energy density functional theory analysis. We have clarified that the structural transition occurs through the interplay among the charge density wavelike lattice modulation with q1/5=(1/5,0,1/5), in-plane dimer ordering, and the uniform lattice deformation. The Ir-Ir dimer formation via a molecular-orbital version of the Jahn-Teller distortion in the Ir-Ir zigzag stripe is found to play the most important role in producing the charge disproportionation state. Angle-resolved photoemission spectroscopy reveals the characteristic features of structural transition, which are in good agreement with the density functional theory bands obtained by the band-unfolding technique.
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.|c_CCMR, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Kyoo
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Sooran
authors.initials: S
authors.lastname: Kim
authors.affiliation: c_CCMR, Pohang University of Science and Technology, Pohang 790-784, Korea.|MPPC_CPM, Pohang University of Science and Technology, Pohang 790-784, Korea.|Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, Dresden D-01187, Germany.
authors.forename: K-T
authors.initials: KT
authors.lastname: Ko
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.|c_CCMR, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Hwangho
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.|c_CCMR, Pohang University of Science and Technology, Pohang 790-784, Korea.|MPPC_CPM, Pohang University of Science and Technology, Pohang 790-784, Korea.|Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: J-H
authors.initials: JH
authors.lastname: Park
authors.affiliation: c_CCMR, Pohang University of Science and Technology, Pohang 790-784, Korea.|Laboratory for Pohang Emergent Materials. Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: J J
authors.initials: JJ
authors.lastname: Yang
authors.affiliation: Laboratory for Pohang Emergent Materials. Pohang University of Science and Technology, Pohang 790-784, Korea.|Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Piscataway, New Jersey 08854, USA.
authors.forename: S-W
authors.initials: SW
authors.lastname: Cheong
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: B I
authors.initials: BI
authors.lastname: Min