title: Electron-hole coupling and the charge density wave transition in TiSe2.
abstract: Angle-resolved photoemission is employed to measure the band structure of TiSe2 in order to clarify the nature of the ( 2 x 2 x 2) charge density wave transition. The results show a very small indirect gap in the normal phase transforming into a larger indirect gap at a different location in the Brillouin zone. Fermi surface topology is irrelevant in this case. Instead, electron-hole coupling together with a novel indirect Jahn-Teller effect drives the transition.
authors.affiliation: Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Kidd
authors.forename: T
authors.initials: T
authors.lastname: Miller
authors.forename: M Y
authors.initials: MY
authors.lastname: Chou
authors.forename: T-C
authors.initials: TC
authors.lastname: Chiang