title: Ultrafast photoinduced insulator-ferromagnet transition in the perovskite manganite Gd0.55Sr0.45MnO3.
abstract: We have investigated the ultrafast spin and charge dynamics in the course of a photoinduced phase transition from an insulator with short-range charge order and orbital order (OO) to a ferromagnetic metal in perovskite-type Gd0.55Sr0.45MnO3. Transient reflectivity changes suggest that the metallic state is formed just after the photoirradiation and decays within approximately 1 ps. The magnetization, however, increases with the time constant of 0.5 ps and decays in approximately 10 ps. The relatively slow increase of the magnetization is attributable to the magnetic-field-induced alignment of ferromagnetic domains in the initially produced metallic state and its slow decay to the partial recovery of the OO.
authors.affiliation: Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8562, Japan. m-matsubara@aist.go.jp
authors.forename: M
authors.initials: M
authors.lastname: Matsubara
authors.forename: Y
authors.initials: Y
authors.lastname: Okimoto
authors.forename: T
authors.initials: T
authors.lastname: Ogasawara
authors.forename: Y
authors.initials: Y
authors.lastname: Tomioka
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura