title: magnetic dispersion and anisotropy in multiferroic BiFeO3.
abstract: We have determined the full magnetic dispersion relations of multiferroic BiFeO3. In particular, two excitation gaps originating from magnetic anisotropies have been clearly observed. The direct observation of the gaps enables us to accurately determine the Dzyaloshinskii-Moriya (DM) interaction and the single ion anisotropy. The DM interaction supports a sizable magnetoelectric coupling in this compound.
authors.affiliation: Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: M
authors.initials: M
authors.lastname: Matsuda
authors.forename: R S
authors.initials: RS
authors.lastname: Fishman
authors.forename: T
authors.initials: T
authors.lastname: Hong
authors.forename: C H
authors.initials: CH
authors.lastname: Lee
authors.forename: T
authors.initials: T
authors.lastname: Ushiyama
authors.forename: Y
authors.initials: Y
authors.lastname: Yanagisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Tomioka
authors.forename: T
authors.initials: T
authors.lastname: Ito