Frequency Shifts and Linewidth Changes of Infrared-Active Phonons in Double-Layered High-Temperature Superconductors

摘要

We calculate frequency shifts and changes in linewidths of infrared-activephonons within a shell model for the bare phononic system coupled to anelectronic double-layer structure with inter-layer charge transfer. Thetheoretical concept is applied to YBaCuO yielding a good description ofexperimental results in the normal state as well as at the transition to thesuperconducting state.