Doping-dependent photon scattering resonance in the model high-temperature superconductor HgBa2CuO4+δ revealed by Raman scattering and optical ellipsometry - Yuan Li; M. Le Tacon; Y. Matiks; A.V. Boris; T. Loew; C.T. Lin; Lu Chen; M.K. Chan; C. Dorow; L. Ji; N. Barišić; X. Zhao; et al. (Physical Review Letters, 2013)