Pairing Fluctuation Theory of Superconducting Properties in Underdoped to Overdoped Cuprates

We propose a theoretical description of the superconducting state of under- to overdoped cuprates, based on the short coherence length of these materials and the associated strong pairing fluctuations. The calculated Tc and the zero temperature excitation gap Δ(0), as a function of hole concentration x, are in semiquantitative agreement with experiment. Although Tc/Δ(0) has a strong non-BCS x dependence, and Δ(T) deviates significantly from the BCS prediction, we obtain, remarkably, quasiuniversal behavior for the superfluid density ρₛ(T)/ρₛ(0) and the Josephson critical current Ic(T)/Ic(0) as a function of T/Tc. Comparison with experiment is addressed.