Superconducting order parameter in heavily overdoped $Bi_2 Sr_2 Ca Cu_2 O_{8+δ}$: a global quantitative analysis

Abstract

A systematic analysis of the complex lineshape at $(π,0)$ of heavily overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ is presented. We show that a coherent component in the quasi-particle excitation is correlated with the superfluid density throughout the entire doping range and suggest it is a direct measure of the order parameter of high temperature superconductors.

4 RevTex4 pages, 4 eps figures (Fig. 3 revised after publication on PRB)