title: Electron-Phonon Coupling in the Bulk of Anatase TiO2 Measured by Resonant Inelastic X-Ray Spectroscopy.
abstract: We investigate the polaronic ground state of anatase TiO2 by bulk-sensitive resonant inelastic x-ray spectroscopy (RIXS) at the Ti L3 edge. We find that the formation of the polaron cloud involves a single 95 meV phonon along the c axis, in addition to the 108 meV ab-plane mode previously identified by photoemission. The coupling strength to both modes is the same within error bars, and it is unaffected by the carrier density. These data establish RIXS as a directional bulk-sensitive probe of electron-phonon coupling in solids.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de Physique des Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Moser
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de Physique des Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Fatale
authors.affiliation: Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan.
authors.forename: P
authors.initials: P
authors.lastname: Krüger
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de Physique des Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Berger
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de Physique des Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Bugnon
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de Physique des Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Magrez
authors.affiliation: Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8526, Japan.|Synchrotron Radiation Research Organization, University of Tokyo, Sayo-cho, Sayo, Hyogo 679-5198, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Niwa
authors.affiliation: Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8526, Japan.|Synchrotron Radiation Research Organization, University of Tokyo, Sayo-cho, Sayo, Hyogo 679-5198, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Miyawaki
authors.affiliation: Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8526, Japan.|Synchrotron Radiation Research Organization, University of Tokyo, Sayo-cho, Sayo, Hyogo 679-5198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de Physique des Nanostructures, CH-1015 Lausanne, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Grioni