Zn-substitution effects on the low-energy quasiparticles in Bi2Sr2CaCu2O8+δ studied by angle-resolved photoemission spectroscopy Original Research Article

We have performed high-resolution angle-resolved photoemission spectroscopy on Bi2Sr2Ca(Cu1−xZnx)2O8+δ (x=0.0, 0.05) to study the Zn-substitution effects on the low-energy quasiparticles. We found that the Zn substitution causes the reduction of the quasiparticle intensity and the superconducting gap, while it does not affect the normal-state band dispersion, the Fermi surface, or the quasiparticle lifetime. This indicates that the Zn substitution locally destroys or hinders the superconducting pairing and as a result decreases the superfluid density, but does not affect the long-range coherence among quasiparticles.