Determination of the Fermi surface in high-T-c superconductors by angle-resolved photoemission spectroscopy - art. no. 224516

We study the normal-state electronic excitations probed by angle-resolved p hotoemission spectroscopy (ARPES) in Bi1.6Pb0.4Sr2CuO6 (Bi2201) and Bi2Sr2C aCu2O8 divided by delta (Bi2212). Our main goal is to establish explicit cr iteria for determining the Fermi surface from ARPES data on strongly intera cting systems where sharply defined quasiparticles do not exist and the dis persion is very weak in parts of the Brillouin zone. Additional complicatio ns arise from strong matrix element variations within the zone. We present detailed results as a function of incident photon energy, and show simple e xperimental tests to distinguish between an intensity drop due to matrix el ement effects and spectral weight loss due to a Fermi crossing. We reiterat e the use of polarization selection rules in disentangling the effect of um klapps due to the BiO superlattice in Bi2212. We conclude that, despite all the complications, the Fermi surface can be determined unambiguously; it i s a single large hole barrel centered about (pi,pi) in both materials.