Exciton Renormalization in Conducting Molecular Solids

The effects upon exciton properties of a coupling between excitons and charge carriers in a conducting molecular solid are calculated employing a canonical transformation. The conducting nature of the system is predicted to introduce a shift to higher energies of the exciton energy; an additional blue shift is predicted if the system is superconducting, yielding in principle a method of detecting the superconducting transition by its effect upon the exciton subsystem. Application of the results to systems other than molecular solids is noted, and a qualitative self-consistent treatment of the effects upon the superconducting properties of the system is given.