PAIRING FLUCTUATION THEORY OF SUPERCONDUCTING PROPERTIES IN UNDERDOPED TO OVERDOPED CUPRATES

We propose a theoretical description of the superconducting state of u nder- to overdoped cuprates, based on the short coherence length of th ese materials and the associated strong pairing fluctuations. The calc ulated T-c, and the zero temperature excitation gap Delta(0), as a fun ction of hole concentration x, are in semiquantitative agreement with experiment. Although T-c/Delta(0) has a strong non-BCS x dependence, a nd Delta(T) deviates significantly from the BCS prediction, we obtain. remarkably, quasiuniversal behavior for the superfluid density rho(s) (T)/rho(s)(0) and the Josephson critical current I-c(T)/I-c(0) as a fu nction of T/T-c. Comparison with experiment is addressed. [S0031-9007( 98)07719-9].