K. MatanY. NambuY. ZhaoT. J. SatoY. FukumotoT. OnoH. TanakaC. BroholmA. PodlesnyakG. EhlersMahidol UniversityThEPTohoku UniversityUniversity of MarylandNIST Center for Neutron ResearchTokyo University of ScienceOsaka Prefecture UniversityTokyo Institute of TechnologyJohns Hopkins UniversityOak Ridge National Laboratory2018-11-092018-11-092014-01-21Physical Review B - Condensed Matter and Materials Physics. Vol.89, No.2 (2014)1550235X109801212-s2.0-84892906285https://repository.li.mahidol.ac.th/handle/20.500.14594/34116High-intensity pulsed neutron scattering reveals a new set of magnetic excitations in the pinwheel valence-bond solid state of the distorted kagome lattice antiferromagnet Rb2Cu3SnF12. The polarization of the dominant dispersive modes (2meV<â ω<7meV) is determined and found consistent with a dimer series expansion with strong Dzyaloshinskii-Moriya interactions (D/J=0.18). A weakly dispersive mode near 5 meV and shifted "ghosts" of the main modes are attributed to the enlarged unit cell below a T=215 K structural transition. Continuum scattering between 8 and 10 meV might be interpreted as a remnant of the kagome spinon continuum [Nature (London) 492, 406 (2012).NATUAS0028-083610.1038/nature11659]. © 2014 American Physical Society.Mahidol UniversityMaterials SciencePhysics and AstronomyArticleSCOPUS10.1103/PhysRevB.89.024414