High-field electron spin resonance (ESR) experiments have been performed on quantum spin systems. A distinct field-induced crossover between the gap-less spinon regime and the gapped sine-Gordon regime is observed for the Heisenberg quantum spin chain; CuBenzoate. In a Shastry and Sutherland model compound SrCu2(BO3)2, a set of multiple-triplet excitations has been resolved by utilizing high-resolution ESR. The splitting of the two-triplet bound state into a few discrete energy levels is considered as the evidence of the extreme localization of the triplet excitations in this compound. The present results indicate the unique and powerful features of ESR in the study of magnetic excitations.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering