High-resolution angle-resolved photoemission study of Pb-substituted Bi2201

We have performed a systematic doping-dependent angle-resolved photoemissio n spectroscopy (ARPES) of Pb-substituted Bi2201 (Bi1.80Pb0.38Sr2.01CuO6-del ta) With high energy (7-11 meV) and momentum (0.01 Angstrom (-1)) resolutio ns. We found that all the samples show a large hole-like Fermi surface cent ered at (pi,pi), whose volume changes systematically as a function of dopin g. The superconducting gap exhibits a d(x2-y2)-like anisotropy with a typic al gap value of 10-15 meV near (pi ,0). By comparing with Bi2Sr2CaCu2O8 (Bi 2212), we found that the size of superconducting gap is well scaled with th e maximum T-c (T-c(max)) Doping-dependence of spectral line shape at (pi ,0 ) is very similar between Bi2201 and Bi2212, while its energy scale is diff erent by a factor of 4, corresponding to the ratio of T-c(max) between the two compounds. These indicate that the superconducting and pseudogap proper ties are characterized by T-c(max) irrespective of the number of CuO2 layer s or the BiO superstructure. (C) 2000 Elsevier Science Ltd. All rights rese rved.