Momentum, Temperature, and Doping Dependence of Photoemission Lineshape and Implications for the Nature of the Pairing Potential in High-TcSuperconducting Materials

Abstract

The anomalous momentum and temperature dependence of the spectral lineshape in data from underdoped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi2212) indicates that the quasiparticles are strongly coupled to collective excitations centered near {bold Q}=({pi},{pi}). The doping dependence of the spectral lineshape and its correlation with the size of the superconducting gap indicate these collective excitations are related to the pairing interaction in high-T{sub c} superconductors, in analogy with phonon induced structures in tunneling spectra of low T{sub c} materials. {copyright} {ital 1997} {ital The American Physical Society}