https://doi.org/10.1007/s100510170083
Strong impact of the electron-photon matrix element on angle-resolved photoelectron spectra of Sr2CuO2Cl2
Department of Physics and Astronomy and Ames Laboratory,
US Department of Energy, Iowa State University,
Ames, Iowa 50011, USA
Received:
10
January
2000
Revised:
15
January
2001
Published online: 15 September 2001
In recent years insight has been gained into the electronic structure of layered cuprates using angle-resolved photoelectron spectroscopy. In many of these studies it is assumed that the electron-photon matrix element follows the trends set by the atomic photoionization cross sections and does not influence lineshape, dispersion and the k-dependence of the spectral intensity. In this study using Sr2CuO2Cl2 as an example it will be shown that the electron-photon matrix element can have a strong impact on both strength and shape of a feature in an angle-resolved photoelectron spectrum of a layered cuprate which can strongly affect information on character and the momentum-dependence of the energy and spectral weight of a state deduced from the spectra. The results of this study put an emphasis on the need to employ the whole parameter range of the ARPES method to get reliable information on the spectral function of cuprates for which purpose synchrotron radiation is an uniquely suited tool.
PACS: 74.72.Jt – Other cuprates / 79.60.-i – Photoemission and photoelectron spectra / 74.25.Jb – Electronic structure
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001