Inelastic Light Scattering from Magnetic Fluctuations inCuGeO3

Magnetic fluctuations in ${\mathrm{CuGeO}}_3$ are studied using inelastic light scattering experiments over a broad temperature range. In the dimerized phase $(T<\mathrm{}14\mathrm{K})$, scattering resulting from maxima in the magnonlike density of states and from spin-phonon coupled modes are reported. In the short-range order regime of the uniform phase $(14<T<\mathrm{}60\mathrm{K})$ the results confirm the existence of a spin-wave continuum, as expected for a one-dimensional quantum Heisenberg chain. At high temperatures $(T>\mathrm{}60\mathrm{K})$ clear evidence is given for the existence of low-dimensional diffusive fluctuations.