ARPES of Pb-Bi2212: new views on old problems.

Sergey Borisenko

Institute for Solid State Research, IFW-Dresden, P.O. Box 270016, D-01171, Dresden, Germany

An overview of the recent photoemission results from the superstructure-free Pb-Bi2212 is presented. We 
re-address several important for HTSC questions intensively studied by the ARPES in the past, paying a 
special attention to the effects originating from the c-axis bilayer splitting. In particular, we derive 
precise set of the tight-binding parameters from the experimentally determined Fermi surfaces and 
velocities for different doping levels. We show that each of the bilayer split Fermi surface sheets 
supports a superconducting gap and these gaps are identical within the experimental error bars. The 
famous peak-dip-hump line shape observed near the (pi,0)-point in the superconducting state turns 
out to be strongly excitation energy dependent and its origin is different in under- and overdoped 
cases. We find a convincing evidence of the coupling between the electrons and a sharp collective mode 
below Tc and estimate the strength of such coupling as a function of doping.

[1] A. A. Kordyuk et al., PRB 66, 014502 (2002) and cond-mat/0208418.
[2] S. V. Borisenko et al., PRB 66 (in press).
[3] A. A. Kordyuk et al., PRL 89, 077003 (2002).
[4] S. V. Borisenko et al., cond-mat/0209435.