Correlated decay of triplet excitations in the Shastry-Sutherland compound SrCu$_2$(BO$_3$)$_2$
| Autor: | Zayed, M. E., Rüegg, Ch., Strässle, Th., Roessli, U. Stuhr B., Ay, M., Mesot, J., Link, P., Pomjakushina, E., Stingaciu, M., Conder, K., Rønnow, H. M. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 113, 067201 (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.113.067201 |
| Popis: | The temperature dependence of the gapped triplet excitations (triplons) in the 2D Shastry-Sutherland quantum magnet SrCu$_2$(BO$_3$)$_2$ is studied by means of inelastic neutron scattering. The excitation amplitude rapidly decreases as a function of temperature while the integrated spectral weight can be explained by an isolated dimer model up to 10~K. Analyzing this anomalous spectral line-shape in terms of damped harmonic oscillators shows that the observed damping is due to a two-component process: one component remains sharp and resolution limited while the second broadens. We explain the underlying mechanism through a simple yet quantitatively accurate model of correlated decay of triplons: an excited triplon is long-lived if no thermally populated triplons are near-by but decays quickly if there are. The phenomenon is a direct consequence of frustration induced triplon localization in the Shastry--Sutherland lattice. Comment: 5 pages, 4 figures |
| Databáze: | arXiv |
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