THE CHARGE BAG MECHANISM OF SUPERCONDUCTIVITY IN CARRIER INJECTED CHARGE-DENSITY WAVE SYSTEMS

A new mechanism is proposed for superconductivity (SC) arising in carrier injected charge density wave (CDW) insulators. It is demonstrated that an attractive interaction between the injected charge carriers is predominantly generated by the exchange of the CDW-amplitude mode, which is a high frequency optic phonon of the lattice distorted CDW state. This attractive interaction then produces pairing and hence superconductivity, whose transition temperature (T(c)) is enhanced due to an increase in the cutoff frequency as well as the density of states at the Fermi level. It is argued that the model can successfully explain the high temperature superconductivity observed in the perovskite compound Ba1-xK(x)BiO3. An understanding of the enhancement of T(c) on intercalation in certain layered transition metal dichalchogenides can also be achieved in terms of this charge bag model.