Spin-phonon interactions in the Raman spectra of one- and two-dimensional quantum spin antiferromagnets

Two-magnon Raman scattering in one-dimensional S = 1/2 quantum spin antiferromagnets Ca2CuO3 and CuGeO3 is found to extend up to 2 pi J, where J is the exchange energy along the chain. The resonant multi-phonon peaks in Ca2CuO3 and undoped high T-C cuprates, and phonon peaks related to the spin-Peierls transition in CuGeO3 are highly asymmetric in the spin-phonon interactions, if the phonon energies are within the two-magnon band and polarizations of incident and scattered light are parallel to each other and to the chain or plane.