title: Bound excitons in Sr2CuO3.
abstract: We investigated temperature dependent optical spectra of the one-dimensional chain compound Sr2CuO3. The charge transfer transition polarized along the chain direction shows a strongly asymmetric line shape as expected in one-dimensional extended Hubbard model. At low temperature, the charge transfer peak shows a large blueshift and reveals additional sharp peaks at the gap. Even though many spectroscopic studies suggest that this material cannot have a bound exciton based on the one-dimensional extended Hubbard model, we attribute the additional sharp peaks to excitons, which come to exist due to the long-range Coulomb interaction.
authors.affiliation: Department of Physics, University of Fribourg, Chemin du Muse 3, Fribourg, Switzerland. kyungwan.kim@gmail.com
authors.forename: K W
authors.initials: KW
authors.lastname: Kim
authors.forename: G D
authors.initials: GD
authors.lastname: Gu
authors.forename: C C
authors.initials: CC
authors.lastname: Homes
authors.forename: T W
authors.initials: TW
authors.lastname: Noh