title: Long-wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3.
abstract: We report a long-wavelength helimagnetic superstructure in bulk samples of the ferrimagnetic insulator Cu2OSeO3. The magnetic phase diagram associated with the helimagnetic modulation inferred from small-angle neutron scattering and magnetization measurements includes a skyrmion lattice phase and is strongly reminiscent of MnSi, FeGe, and Fe(1-x)Co(x)Si, i.e., binary isostructural siblings of Cu2OSeO3 that order helimagnetically. The temperature dependence of the specific heat of Cu2OSeO3 is characteristic of nearly critical spin fluctuations at the helimagnetic transition. This provides putative evidence for effective spin currents as the origin of enhancements of the magnetodielectric response instead of atomic displacements considered so far.
authors.affiliation: Technische Universität München, Physik-Department E21, D-85748 Garching, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Adams
authors.forename: A
authors.initials: A
authors.lastname: Chacon
authors.forename: M
authors.initials: M
authors.lastname: Wagner
authors.forename: A
authors.initials: A
authors.lastname: Bauer
authors.forename: G
authors.initials: G
authors.lastname: Brandl
authors.forename: B
authors.initials: B
authors.lastname: Pedersen
authors.forename: H
authors.initials: H
authors.lastname: Berger
authors.forename: P
authors.initials: P
authors.lastname: Lemmens
authors.forename: C
authors.initials: C
authors.lastname: Pfleiderer