title: Activation of coherent lattice phonon following ultrafast molecular spin-state photo-switching: A molecule-to-lattice energy transfer.
abstract: We combine ultrafast optical spectroscopy with femtosecond X-ray absorption to study the photo-switching dynamics of the [Fe(PM-AzA)2(NCS)2] spin-crossover molecular solid. The light-induced excited spin-state trapping process switches the molecules from low spin to high spin (HS) states on the sub-picosecond timescale. The change of the electronic state (<50 fs) induces a structural reorganization of the molecule within 160 fs. This transformation is accompanied by coherent molecular vibrations in the HS potential and especially a rapidly damped Fe-ligand breathing mode. The time-resolved studies evidence a delayed activation of coherent optical phonons of the lattice surrounding the photoexcited molecules.
authors.affiliation: Institute de Physique de Rennes , UMR 6251 University Rennes 1-CNRS, 35042 Rennes, France.
authors.forename: A
authors.initials: A
authors.lastname: Marino
authors.affiliation: Institute de Physique de Rennes , UMR 6251 University Rennes 1-CNRS, 35042 Rennes, France.
authors.forename: M
authors.initials: M
authors.lastname: Cammarata
authors.affiliation: CNRS, Université de Bordeaux , ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac 33608, France.
authors.forename: S F
authors.initials: SF
authors.lastname: Matar
authors.affiliation: CNRS, Université de Bordeaux , ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac 33608, France.
authors.forename: J-F
authors.initials: JF
authors.lastname: Létard
authors.affiliation: CNRS, Université de Bordeaux , ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac 33608, France.
authors.forename: G
authors.initials: G
authors.lastname: Chastanet
authors.affiliation: LCLS, SLAC National Laboratory , Menlo Park, California 94025, USA.
authors.forename: M
authors.initials: M
authors.lastname: Chollet
authors.affiliation: LCLS, SLAC National Laboratory , Menlo Park, California 94025, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Glownia
authors.affiliation: LCLS, SLAC National Laboratory , Menlo Park, California 94025, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Lemke
authors.affiliation: Institute de Physique de Rennes , UMR 6251 University Rennes 1-CNRS, 35042 Rennes, France.
authors.forename: E
authors.initials: E
authors.lastname: Collet