title: Raman scattering study of anomalous spin, charge, and lattice dynamics in the charge-ordered phase of Bi1-xCaxMnO3 (x > 0.5).
abstract: We report an inelastic light scattering study of the effects of charge ordering on the spin, charge, and lattice dynamics of Bi1-xCaxMnO3 (x>0.5). We find that charge ordering results in anomalous phonon behavior, such as the appearance of "activated" modes. More significantly, however, the transition to the charge-ordered phase results in the appearance of a quasielastic scattering response with the symmetry of the spin-chirality operator ( T(1g)); this scattering response is thus indicative of magnetic or chiral spin fluctuations in the antiferromagnetic charge-ordered phase.
authors.affiliation: Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yoon
authors.forename: M
authors.initials: M
authors.lastname: Rübhausen
authors.forename: S L
authors.initials: SL
authors.lastname: Cooper
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: S W
authors.initials: SW
authors.lastname: Cheong