Magnetic ground state and magnon-phonon interaction in multiferroic h-YMnO${}_3$

Abstract

Inelastic neutron scattering has been used to study the magneto-elastic excitations in the multiferroic manganite hexagonal YMnO${}_3$. An avoided crossing is found between magnon and phonon modes close to the Brillouin zone boundary in the $(a,b)$-plane. Neutron polarization analysis reveals that this mode has mixed magnon-phonon character. An external magnetic field along the $c$-axis is observed to cause a linear field-induced splitting of one of the spin wave branches. A theoretical description is performed, using a Heisenberg model of localized spins, acoustic phonon modes and a magneto-elastic coupling via the single-ion magnetostriction. The model quantitatively reproduces the dispersion and intensities of all modes in the full Brillouin zone, describes the observed magnon-phonon hybridized modes, and quantifies the magneto-elastic coupling. The combined information, including the field-induced magnon splitting, allows us to exclude several of the earlier proposed models and point to the correct magnetic ground state symmetry, and provides an effective dynamic model relevant for the multiferroic hexagonal manganites.

arXiv comment12 pages, 10 figures

References in corpus (19)

• Linear spin wave theory for single-Q incommensurate magnetic structures
• Magnetic Order and Spin Dynamics in Ferroelectric HoMnO${}_3$
• Magnetic dispersion and anisotropy in multiferroic BiFeO3
• Unconventional spin fluctuations in the hexagonal antiferromagnet YMnO${}_3$
• Spin wave measurements over the full Brillouin zone of multiferroic BiFeO3
• Spontaneous decays of magneto-elastic excitations in noncollinear antiferromagnet (Y,Lu)MnO3
• Brillouin light scattering spectroscopy of parametrically excited dipole-exchange magnons
• Temperature-Dependent Interplay of Dzyaloshinskii-Moriya Interaction and Single-Ion Anisotropy in Multiferroic BiFeO${}_3$
• Hexagonal RMnO${}_3$: a model system for 2D triangular lattice antiferromagnets
• Quantum Heisenberg antiferromagnets in a uniform magnetic field: nonanalytic magnetic field dependence of the magnon spectrum
• Lattice and spin excitations in multiferroic h-YMnO3
• Magnon-phonon coupling and two-magnon continuum in two-dimensional triangular antiferromagnet CuCrO2
• Magnetism in Geometrically Frustrated YMnO3 Under Hydrostatic Pressure Studied with Implanted Muons
• Spin fluctuations in the stacked-triangular antiferromagnet YMnO3
• An ab initio study of magneto-electric coupling of $\mathrm{YMn}{\mathrm{O}}_3$
• Analysis of the multiferroicity in the hexagonal manganite YMnO3
• Magnetic properties of a metal-organic antiferromagnet on a distorted honeycomb lattice
• Magnetoelastic effects in multiferroic YMnO${}_3$
• Neutron inelastic scattering measurements of low energy phonons in the multiferroic BiFeO3

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• Hybridization and Decay of Magnetic Excitations in two-dimensional Triangular Lattice Antiferromagnets
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• Characterizing the diffuse continuum excitations in the classical spin liquid $h$-YMnO${}_3$
• The studies on phonons and magnons in (Ni80Fe20/Au/Co/Au) multilayers of different number of repetitions