Phonon-induced anomalous Raman spectra in undoped high-T-c cuprates

Abstract

In order to describe a shoulder peak structure near 4J in the magnon Raman spectra of undoped high-T-c cuprates, we have explored the phonon contribution to the Raman spectra. Incorporating the magnon-phonon Hamiltonian in the spin-wave theory, we have evaluated the two-magnon Raman spectral function originating from the lowest-order magnon-phonon-magnon scattering. It is found that phonons induce a shoulder peak near 4J besides the dominant two-magnon peak near 3J, in agreement with experiments.