Low-energy magnons in the chiral ferrimagnet Cu2OSeO3: A coarse-grained approach

Article

关键词: NEUTRON-SCATTERING;    VISUALIZATION;    SOFTWARE;   

DOI  :  10.1103/PhysRevB.101.144411

来源: SCIE

【 摘 要 】

We report a comprehensive neutron scattering study of low energy magnetic excitations in the breathing pyrochlore helimagnetic Cu2OSeO3. Fully documenting the four lowest energy magnetic modes that leave the ferrimagnetic configuration of the strong tetrahedra intact (vertical bar(h) over bar omega vertical bar < 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 complex anisotropic intercluster interactions is obtained.

【 授权许可】

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