Spins and phonons in the spin-Peierls compound CuGeO3

Vibrational and spin dynamical properties of CuGeO3 are studied using inelastic light scattering techniques as a function of temperature and magnetic field. Apart from one phonon processes, also two phonon scattering has been observed. Two spin gaps are observed in the dimerised phase, which disappear in the high field incommensurate phase. Raman data show that well-defined propagative modes still exist in the high field phase, whereas infrared absorption shows the presence of a new gap which is attributed to the Zeeman splitting of the ground state in the high field phase.