Low energy magnons in the chiral ferrimagnet ${\text{Cu}}_2{\text{OSeO}}_3$: a coarse-grained approach

Abstract

We report a comprehensive neutron scattering study of low energy magnetic excitations in the breathing pyrochlore helimagnetic ${\text{Cu}}_2{\text{OSeO}}_3$. Fully documenting the four lowest energy magnetic modes that leave the ferrimagnetic configuration of the "strong tetrahedra" intact ($|\hslash \omega |<13$ meV), we find gapless quadratic dispersion at the $\Gamma$ point for energies above 0.2 meV, two doublets separated by 1.6(2) meV at the $R$ point, and a bounded continuum at the $X$ point. Our constrained rigid spin cluster model relates these features to Dzyaloshinskii-Moriya (DM) interactions and the incommensurate helical ground state. Combining conventional spin wave theory with a spin cluster form-factor accurately reproduces the measured equal time structure factor through multiple Brillouin zones. An effective spin Hamiltonian describing the complex anisotropic inter-cluster interactions is obtained.

20 pages, 12 figures, 4 tables

References in corpus (12)

• Mantid - Data Analysis and Visualization Package for Neutron Scattering and $\mu SR$ Experiments
• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Double crystallographic groups and their representations on the Bilbao Crystallographic Server
• Spontaneous Magnon Decays
• Formation and rotation of skyrmion crystal in the chiral-lattice insulator Cu2OSeO3
• Observation of two independent skyrmion phases in a chiral magnetic material
• Strong Dzyaloshinskii-Moriya Interaction and Origin of Ferroelectricity in Cu2OSeO3
• The quantum origins of skyrmions and half-skyrmions in Cu2OSeO3
• Establishing the fundamental magnetic interactions in the chiral skyrmionic Mott insulator Cu2OSeO3 by terahertz electron spin resonance
• Reorientations, relaxations, metastabilities and multidomains of skyrmion lattices
• Ballistic magnon heat conduction and possible Poiseuille flow in the helimagnetic insulator Cu${}_2$OSeO${}_3$
• Spin excitations in the skymion host Cu2OSeO3

Cited by in corpus (9)

• Continuous spin excitations in the three-dimensional frustrated magnet K2Ni2(SO4)3
• Confined dipole and exchange spin waves in a bulk chiral magnet with Dzyaloshinskii-Moriya interaction
• Momentum-dependent magnon lifetime in the metallic non-collinear triangular antiferromagnet CrB2
• Spin dynamics of triple-Q magnetic orderings in a triangular lattice: Implications for multi-Q orderings in general two-dimensional lattices
• Hybrid magnetization dynamics in ${\text{Cu}}_{\text{2}}{\text{OSeO}}_{\text{3}}$/$\mathrm{NiFe}$ heterostructures
• Quintuplet condensation in the skyrmionic insulator Cu2OSeO3 at ultrahigh magnetic fields
• Helical spin dynamics in Cu${}_2$OSeO${}_3$ as measured with small-angle neutron scattering
• The influence of antiferromagnetic spin cantings on the magnetic helix pitch in cubic helimagnets
• Spin and Orbital Effects on Asymmetric Exchange Interaction in Polar Magnets: M(IO3)2 (M = Cu, Mn)