Vi. Belinicher et al., GENERALIZED T-T'-J MODEL - PARAMETERS AND SINGLE-PARTICLE SPECTRUM FOR ELECTRONS AND HOLES IN COPPER OXIDES, Physical review. B, Condensed matter, 53(1), 1996, pp. 335-342
A microscopically based Hamiltonian of the generalized t-t'-J model is
presented. Two types of the additional t' terms are discussed. The nu
merical range of the amplitudes corresponding to the additional t' ter
ms for the real CuO2 planes is derived from the three-band model calcu
lations. Using the variational spin-polaron approach the single-carrie
r dispersions in the generalized t-t'-J model are calculated both for
the hole- and electron-doped systems. The hole and electron band minim
a are found to be at points (+/-pi/2,+/-pi/2), (0,+/-pi), and (+/-pi 0
), respectively. The band minima shifts \Delta((0,pi)-(pi/2,pi/2))\ ar
e not small (similar to J). The bandwidths for both cases of doping ar
e found to be 1.5-4.0 times larger than those in the t-J model.