Resonant two-magnon Raman scattering in cuprate antiferromagnetic insulators
We present results of low-temperature two-magnon resonance Raman excitation profile measurements for single-layer Sr2CuO2Cl2 and bilayer YBa2Cu3O6+δ antiferromagnets over the excitation region from 1.65 to 3.05 eV. These data reveal composite structure of the two-magnon line shape and strong nonmonotic dependence of the scattering intensity on excitation energy. We analyze these data using the triple resonance theory of Chubukov and Frenkel Phys. Rev. Lett. 74 3057 (1995) and deduce information about magnetic interaction and band parameters in these materials.