title: Spin-chirality-driven ferroelectricity on a perfect triangular lattice antiferromagnet.
abstract: Magnetic field (B) variation of the electrical polarization P(c) (∥c) of the perfect triangular lattice antiferromagnet RbFe(MoO(4))(2) is examined up to the saturation point of the magnetization for B⊥c. P(c) is observed only in phases for which chirality is predicted in the in-plane magnetic structures. No strong anomaly is observed in P(c) at the field at which the spin modulation along the c axis, and hence the spin helicity, exhibits a discontinuity to the commensurate state. These results indicate that the ferroelectricity in this compound originates predominantly from the spin chirality, the explanation of which would require a new mechanism for magnetoferroelectricity. The obtained field-temperature phase diagram of ferroelectricity agree well with those theoretically predicted for the spin chirality of a Heisenberg spin triangular lattice antiferromagnet.
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Mitamura
authors.affiliation: Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Watanuki
authors.affiliation: Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kaneko
authors.affiliation: Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Onozaki
authors.affiliation: Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Amou
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kittaka
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan and Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: R
authors.initials: R
authors.lastname: Kobayashi
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Shimura
authors.affiliation: Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Yamamoto
authors.affiliation: Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chi
authors.affiliation: Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakakibara