Hamburg 2001 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 11: Fachsymposium: Eindimensionale Übergangsmetalle
TT 11.2: Hauptvortrag
Dienstag, 27. März 2001, 15:00–15:30, A
Raman Scattering on low-dimensional Transition Metal Oxides — •P. Lemmens and G. Güntherodt — 2. Physikalisches Institut, RWTH Aachen, 52056 Aachen
In low-dimensional spin systems with a spin gap Δ the existence of
unusual magnetic excitations with singlet character is expected. These
well defined modes or bound states have energies that are renormalized
with respect to 2Δ. Recent Raman scattering studies on several
transition metal oxides, that contain Cu2+ or V4+ cations as
dimers, ladders or tetrahedra, do indeed observe excitations that are
clearly related to the spin gap of the respective system. We will discuss
the present experimental situation with a special emphasis on the
implication of spin topology, spin frustration and spin-phonon interaction
on the binding energy and multiplicity of these modes.
Work supported by DFG.