We investigate the electron-energy loss spectrum of one-dimensional undoped CuO3 chains within an extended multi-band Hubbard model and an extended one-band Hubbard model, using the standard Lanczos algorithm. Short-range intersite Coulomb interactions are explicitly included in these models, and long-range interactions are treated in random-phase approximation. The results for the multi-band model with standard parameter values agree very well with experimental spectra of Sr2CuO3. In particular, the width of the main structure is correctly reproduced for all values of momentum transfer. It is shown for both models that intersite Coulomb interactions mainly lead to an energy shift of the spectra. We find no evidence for enhanced intersite interactions in Sr2CuO3.
@article{arxiv.cond-mat/0012287,
title = {Realistic description of electron-energy loss spectroscopy for One-Dimensional Sr$_2$CuO$_3$},
author = {A. Huebsch and J. Richter and C. Waidacher and K. W. Becker and W. von der Linden},
journal= {arXiv preprint arXiv:cond-mat/0012287},
year = {2009}
}