Application of an Extended Eliashberg Theory to High-T_c Cuprates

Abstract

In recent years a unified phenomenological picture for the hole doped high-T_c cuprates has emerged for a spin and charge spectroscopy. Spectral anomalies have been interpreted as evidence of charge carrier coupling to a collective spin excitation present in the optical conductivity, in ARPES (angular resolved photoemission), and in tunneling data. These anomalies can be used to derive an approximate picture of a charge carrier-exchange boson interaction spectral density I^2 chi(omega) which is then be used within an extended Eliashberg formalism to analyze normal and superconducting properties of optimally doped and overdoped cuprates. This paper reviews recent developments and demonstrates the sometimes astonishing agreement between experiment and theoretical prediction.