title: Ultrafast optical switching to a metallic state by photoinduced mott transition in a halogen-bridged nickel-chain compound.
abstract: We demonstrate the ultrafast photoinduced Mott transition from a charge transfer insulator to a metal in a halogen-bridged Ni-chain compound by pump-probe reflection spectroscopy. Upon the irradiation of a 130-femtosecond laser pulse, the spectral weight of the gap transition is transferred to the inner-gap region. When the photoexcitation density exceeds 0.1/Ni site, the Drude-like high-reflection band appears in the infrared region, signaling the formation of a metallic state. The photogeneration of the metallic state and the subsequent recovery to the original gapped state occur within a few picoseconds.
authors.affiliation: Correlated Electron Research Center (CERC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8564, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Iwai
authors.forename: M
authors.initials: M
authors.lastname: Ono
authors.forename: A
authors.initials: A
authors.lastname: Maeda
authors.forename: H
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: H
authors.initials: H
authors.lastname: Kishida
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura