Pairing Fluctuation Theory of Superconducting Properties in Underdoped to Overdoped Cuprates

Abstract

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 ${T}_{c}$ and the zero temperature excitation gap $\ensuremath{\Delta}(0)$, as a function of hole concentration $x$, are in semiquantitative agreement with experiment. Although ${T}_{c}/\ensuremath{\Delta}(0)$ has a strong non-BCS $x$ dependence, and $\ensuremath{\Delta}(T)$ deviates significantly from the BCS prediction, we obtain, remarkably, quasiuniversal behavior for the superfluid density ${\ensuremath{\rho}}_{s}(T)/{\ensuremath{\rho}}_{s}(0)$ and the Josephson critical current ${I}_{c}(T)/{I}_{c}(0)$ as a function of $T/{T}_{c}$. Comparison with experiment is addressed.