EXPERIMENTAL AND THEORETICAL CONSTRAINTS OF BIPOLARONIC SUPERCONDUCTIVITY IN HIGH T-C MATERIALS - AN IMPOSSIBILITY

The bipolaronic scenario for high T-c superconductivity is critically examined. The underlying assumption that at low temperatures all the c harge carriers exist in the form of itinerant bipolarons is shown to b e incompatible on theoretical and experimental grounds. Superfluidity of such bipolarons cannot give the values of T-c nor explain the fermi onic nature of the quasiparticles observed in the cuprates.