title: Magnetodielectric detection of magnetic quadrupole order in Ba(TiO)Cu4(PO4)4with Cu4O12square cupolas.
abstract: In vortex-like spin arrangements, multiple spins can combine into emergent multipole moments. Such multipole moments have broken space-inversion and time-reversal symmetries, and can therefore exhibit linear magnetoelectric (ME) activity. Three types of such multipole moments are known: toroidal; monopole; and quadrupole moments. So far, however, the ME activity of these multipole moments has only been established experimentally for the toroidal moment. Here we propose a magnetic square cupola cluster, in which four corner-sharing square-coordinated metal-ligand fragments form a noncoplanar buckled structure, as a promising structural unit that carries an ME-active multipole moment. We substantiate this idea by observing clear magnetodielectric signals associated with an antiferroic ME-active magnetic quadrupole order in the real material Ba(TiO)Cu4(PO4)4. The present result serves as a useful guide for exploring and designing new ME-active materials based on vortex-like spin arrangements.
authors.affiliation: Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Babkevich
authors.affiliation: Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sera
authors.affiliation: Department of Physics, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Toyoda
authors.affiliation: ISIR-SANKEN, Osaka University, Ibaraki 567-0047, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamauchi
authors.affiliation: Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.|Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
authors.forename: G S
authors.initials: GS
authors.lastname: Tucker
authors.affiliation: Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Martius
authors.affiliation: Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Fennell
authors.affiliation: ISIS facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK.
authors.forename: P
authors.initials: P
authors.lastname: Manuel
authors.affiliation: ISIS facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK.
authors.forename: D D
authors.initials: DD
authors.lastname: Khalyavin
authors.affiliation: ISIS facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK.
authors.forename: R D
authors.initials: RD
authors.lastname: Johnson
authors.affiliation: Department of Physics, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.affiliation: Department of Physics, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nozue
authors.affiliation: Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: H M
authors.initials: HM
authors.lastname: Rønnow
authors.affiliation: Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kimura