title: Driving Spin Excitations by Hydrostatic Pressure in BiFeO(3).
abstract: Optical spectroscopy has been combined with computational and theoretical techniques to show how the spin dynamics in the model multiferroic BiFeO(3) responds to the application of hydrostatic pressure and its corresponding series of structural phase transitions from R3c to the Pnma phases. As pressure increases, multiple spin excitations associated with noncollinear cycloidal magnetism collapse into two excitations, which show jump discontinuities at some of the ensuing crystal phase transitions. The effective Hamiltonian approach provides information on the electrical polarization and structural changes of the oxygen octahedra through the successive structural phases. The extracted parameters are then used in a Ginzburg-Landau model to reproduce the evolution with pressure of the spin wave excitations observed at low energy, and we demonstrate that the structural phases and the magnetic anisotropy drive and control the spin excitations.
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet 75205 Paris Cedex 13, France.
authors.forename: J
authors.initials: J
authors.lastname: Buhot
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet 75205 Paris Cedex 13, France.
authors.forename: C
authors.initials: C
authors.lastname: Toulouse
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet 75205 Paris Cedex 13, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Gallais
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet 75205 Paris Cedex 13, France.
authors.forename: A
authors.initials: A
authors.lastname: Sacuto
authors.affiliation: Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada, V8W 2Y2.
authors.forename: R
authors.initials: R
authors.lastname: de Sousa
authors.affiliation: Electronic Materials Research Laboratory-Key Laboratory of the Ministry of Education, and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.affiliation: Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA.
authors.forename: L
authors.initials: L
authors.lastname: Bellaiche
authors.affiliation: Unité Mixte de Physique CNRS/Thales, 1 avenue Augustin Fresnel, Campus de l'Ecole Polytechnique, F-91767 Palaiseau, France et Université Paris-Sud, 91405 Orsay, France.
authors.forename: M
authors.initials: M
authors.lastname: Bibes
authors.affiliation: Unité Mixte de Physique CNRS/Thales, 1 avenue Augustin Fresnel, Campus de l'Ecole Polytechnique, F-91767 Palaiseau, France et Université Paris-Sud, 91405 Orsay, France.
authors.forename: A
authors.initials: A
authors.lastname: Barthélémy
authors.affiliation: Service de Physique de l'Etat Condensé, CEA Saclay, IRAMIS, SPEC (CNRS URA 2464), F-91191 Gif sur Yvette, France.
authors.forename: A
authors.initials: A
authors.lastname: Forget
authors.affiliation: Service de Physique de l'Etat Condensé, CEA Saclay, IRAMIS, SPEC (CNRS URA 2464), F-91191 Gif sur Yvette, France.
authors.forename: D
authors.initials: D
authors.lastname: Colson
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet 75205 Paris Cedex 13, France.
authors.forename: M
authors.initials: M
authors.lastname: Cazayous
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS, Université Paris Diderot, Bâtiment Condorcet 75205 Paris Cedex 13, France.
authors.forename: M-A
authors.initials: MA
authors.lastname: Measson