Evidence for a Fano-type interaction of infrared active phonons with electronic excitations in Tl 2Ba 2Ca 2Cu 3O 10

Abstract

In this paper we report evidence for a Fano-type interaction of infrared active phonons with electronic excitations in superconducting Tl 2Ba 2Ca 2Cu 3O 10. We have analyzed the dielectric function obtained from reflectivity data of a polycrystalline sample. We take into account infrared active phonons, an infrared active electronic continuum, that we describe by an extended Drude model, and a resonance interaction between the electronic and phononic excitations. We found frequency shifts caused by the resonance interaction of several percent of the eigenfrequencies of the phonons.