Superconducting coherent quasiparticle weight in high- Tc superconductor from angle-resolved photoemission

We study the doping and temperature dependence of the single-particle coherent weight, z A, for high- T c superconductors Bi 2Sr 2CaCu 2O 8+ x using angle-resolved photoemission. We find that at low temperatures the coherent weight z A at (π,0) is proportional to the carrier concentration x and that the temperature-dependence of z A is similar to that of the c-axis superfluid density. We show that, for a wide range of carrier concentration, the superconducting transition temperature scales with the product of the low-temperature coherent weight and the maximum superconducting gap.