Effect of polarization of the exciting light on resonant photoelectron emission from La2CuO4+δ single crystals
Mikheeva M. N., Nazin V. G., Svishchev A. V., Tsetlin M. B., Law D. S.-L.
A resonant increase in the emission from electron states with a binding energy = 6 eV at an exciting-photon energy 17 eV has been observed in photoelectron spectra of the valence band of La2Cu04+^ single crystals. The intensity of the resonant-emission peak is comparable to the maximum of the valence band. An effect of the polarization of the exciting light on the nature of the resonance has been observed for the first time: As the orientation of the polarization vector with respect to the crystallographic axes is varied, changes occur in the binding energy of the resonant peak and in the resonant emission frequency. The effect, with very slight differences, is observed for both insulating and superconducting samples. The experimental data are discussed within the framework of the theory of resonant photoemission. © 1994 American Institute of Physics.