Münster 1999 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 15: Postersitzung II: Elektronische Eigenschaften (1-12), Josephson-Kontakte (13-27), Heavy Fermions (28-40), Theorie HTSL (41-48), M-I-Überg
änge, Korrelierte Systeme (49-79)
TT 15.73: Poster
Mittwoch, 24. März 1999, 14:30–18:00, Foy
Electronic structure of antiferromagnetic three-band Hubbard model — •M. Sugihara1, M. A. Ikeda2, and P. Entel1 — 1Theoretische Physik, Universit"at Duisburg, 47048, Duisburg — 2Department of Physics, Aoyama Gakuin University, 157-8572, Tokyo
We discuss the electronic structure of a single CuO2 layer of high-Tc cuprate materials by the three-band Hubbard model. The three-band Hubbard model has already been discussed in some theoretical works [1], however, only a few of them considered the presence of antiferromagnetic (AF) order at the copper sites. We treat the strong but finite intra-atomic Coulomb correlation at the copper sites within the Hubbard-I scheme and determine the electronic structure of a single CuO2 layer with AF order [2]. The results show a decrease of the AF order with doping of holes or electrons in qualitative agreement with the experimental results. In particular we show the existence of a small Fermi surface and AF nested bands near the Fermi level as was recently observed for low doping levels of Bi2Sr2CaCu2O8 by angle-resolved photoemission spectroscopy [3]. The AF insulating state we obtained is fundamentally different from the prevailing view of the simple charge transfer insulator and the experimental data by Marshall et al. [3] include an evidence to out view.
[1] P. Entel and J. Zielinski, Phys. Rev. B, 42, 307 (1990).
[2] M. Sugihara, M. A. Ikeda, and P. Entel, Phys. Rev. B, 57, 11760 (1998).
[3] D. S. Marshall et al., Phys. Rev. Lett, 76, 4841 (1996).