Excitonic mechanism superconductivity

Many authors have discussed the excitonic mechanism (36-37.) of superconductivity, in which the effective attractive interaction between conduction electrons originates from virtual excitations of excltons rather than phonons. The basic idea of the models proposed is that conduction electrons residing on the conducting filament (or plane) induce electronic transitions on nearby easily polarizable molecules (or complexes), which result in an effective attractive interaction between conduction electrons. As perhaps a striking realization of the excitonic mechanism of superconductivity,... 

The present model for nerve impulse resembles closely the exciton mechanism of high-temperature superconductivity, as put forward by Little and Ginzburg. Little s polymer consists of a polyene spine with polarizable dye side chains, the latter forming the exciton band. Ginzburg proposes high-temperature superconductivity to be found in thin metallic films placed between highly dielectric layers. " ... 

This trend goes further away from the peculiar physical properties which were predicted for 1-D electronic systems. There are the Peierls-Frdhlich CDW collective transport mechanism [30], and Little s excitonic mechanism for high-T superconductivity [33], in which an electronically polarizable entity is used instead of the ionic lattice. It is necessary to conclude that there is a divorce between the experimental results and these initial attractive concepts. 

---