A photoemission study to confirm the second order nature of anomalous O 2s resonant enhancement of Bi2Sr2CaCu2O8(001) fermi level states

Abstract We have performed a synchrotron-excited angle resolved photoemission study of the valence band region of cleaved Bi 2 Sr 2 CaCu 2 O 8 (001) samples. By recording spectra between 16 and 30eV on two separate beamlines with differing second order light contributions, we have investigated the origin of previously reported “anomalous” O 2s resonant enhancement of Fermi level states, in which the features showing resonant enhancement apparently disperse with photon energy. Our results indicate that anomalous O 2s resonant enhancement may be explained by second order effects.