Superconductive Excitations and the Infrared Vibronic Spectra of BSCCO
  The oxygen dopant concentration dependence of the "quasiparticle" feature at 600-750 cm-1 of the infrared spectrum of Bi2Sr2CaCu2O8+delta (BSCCO), lying near and above the top of the host phonon spectrum at 600 cm-1, is strongly correlated with superconductivity. Using parameter-free topological methods, theory assigns this feature to split apical oxygen interstitials. It explains both the qualitative similarities and the quantitative differences between "quasiparticle" features identified in infrared and phtoemission data, as well as identifying new features in the infrared spectra. 
J.C. Phillips (Rutgers University)