Experimental and theoretical constraints of bipolaronic superconductivity in high Tc materials:: An impossibility

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