Regensburg 2000 – scientific programme
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TT: Tiefe Temperaturen
TT 16: Eindimensionale Spinsysteme
TT 16.7: Talk
Wednesday, March 29, 2000, 16:45–17:00, H18
Consistent Mapping of Spectroscopic Data onto Thermodynamic Quantities in the low-dimensional Spin Dimer Compound SrCu2(BO3)2 — •P. Lemmens1, M. Grove1, M. Fischer1, N. van Eldik1, G. Güntherodt1, H. Kagejama2, K. Onizuka2, and Y. Ueda2 — 12. Physikalisches Institut, RWTH Aachen, 52056 Aachen, Germany — 2ISSP, University of Tokyo, Tokyo 106-8666, Japan
The compound SrCu2(BO3)2 is a quantum spin system with an
arrangement of orthogonal spin dimers, an exact singlet ground state
and a spin gap Δ01=34K. Triplet excitations in this
compound are extremely localized and strongly interacting due to the
strong inherent frustration. In Raman light scattering experiments,
in addition to magnetic bound states with energies close to
2Δ01, a continuum of triplet excitations and quasielastic
scattering are observed. The intensities of these scattering
contributions were successfully mapped onto thermodynamic data, i.e.
the magnetic contribution to the specific heat and the
susceptibility. A comparison of the magnetic bound states with
similar states found in dimerized spin chain and spin ladder systems
allows to draw conclusions about the importance of the exchange
topology for the triplet-triplet interaction.
Work supported by DFG through SFB 341.