UC Irvine

Inelastic light scattering studies of La2CuO4, both pure and doped with lead, over the energy range 0–1 have revealed the presence of high-frequency A1g scattering components, in the spectral region 3500–6000 cm-1, while also providing the complete line shape for the previously reported spin-pair mode of B1g symmetry. Two main bands, broad and overlapping, are observed in this region with maxima near 3500 and 5200 cm-1. The various spectral features show different resonance behavior. We suggest that a model based upon coupled spin and charge excitations will be required to describe these spectra.