title: Ferroelectricity induced by spin-dependent metal-ligand hybridization in Ba₂CoGe₂O₇.
abstract: We have investigated the variation of induced ferroelectric polarization under a magnetic field with various directions and magnitudes in a staggered antiferromagnet Ba₂CoGe₂O₇. While the ferroelectric polarization cannot be explained by the well-accepted spin current model nor the exchange striction mechanism, we have shown that it is induced by the spin-dependent p-d hybridization between the transition metal (Co) and ligand (O) via the spin-orbit interaction. On the basis of the correspondence between the direction of electric polarization and the magnetic state, we have also demonstrated the electrical control of the magnetization direction.
authors.affiliation: Multiferroics Project, ERATO, Japan Science and Technology Agency (JST), c/o Department of Applied Physics, University of Tokyo, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Murakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Onose
authors.forename: S
authors.initials: S
authors.lastname: Miyahara
authors.forename: N
authors.initials: N
authors.lastname: Furukawa
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura