BAND-STRUCTURE, MAGNETIC FLUCTUATIONS, AND QUASI-PARTICLE NATURE OF THE 2-DIMENSIONAL 3-BAND HUBBARD-MODEL

A single hole doped into the CuO2 plane of a high-T(c) superconductor is studied via exact calculations of the three-band Hubbard model (large-U limit) on a 4 X 4 periodic cluster. The quasiparticle band has its bottom at k = (pi/2, pi/2) and disperses strongly towards GAMMA and X with a dispersion 1.7J(dd) = 0.22 eV. The quasiparticle has a nearly isotropic effective mass (approximately 4m(e)) and the dressing effects are well localized (approximately 8 angstrom) with characteristic features of both the three-spin polaron and the Zhang-Rice singlet (although solutions of the t-J model are substantially different).