title: Ultrafast optical nonlinearity in the quasi-one-dimensional mott insulator Sr2CuO3
abstract: We report strong instantaneous photoinduced absorption in the quasi-one-dimensional Mott insulator Sr2CuO3 in the IR spectral region. The observed photoinduced absorption is to an even-parity two-photon state that occurs immediately above the absorption edge. Theoretical calculation based on a two-band extended Hubbard model explains the experimental features and indicates that the strong two-photon absorption is due to a very large dipole coupling between nearly degenerate one- and two-photon states. Room temperature picosecond recovery of the optical transparency suggests the strong potential of Sr2CuO3 for all-optical switching.
authors.affiliation: Department of Applied Physics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.initials: T
authors.lastname: Ogasawara
authors.initials: M
authors.lastname: Ashida
authors.initials: N
authors.lastname: Motoyama
authors.initials: H
authors.lastname: Eisaki
authors.initials: S
authors.lastname: Uchida
authors.initials: Y
authors.lastname: Tokura
authors.initials: H
authors.lastname: Ghosh
authors.initials: A
authors.lastname: Shukla
authors.initials: S
authors.lastname: Mazumdar
authors.initials: M
authors.lastname: Kuwata-Gonokami