Quasiparticle energy dispersion in doped two dimensional quantum antiferromagnets

The quasiparticle dispersion in the one-hole t-t'-t"-J model is studied. Both the finite-size diagonalization and the self-consistent Born approximation calculations have been performed and compared. The quasiparticle band structures in the hole and electron doped high-Tc cuprates are qualitatively different. In the hole doped compounds, the band maxima locate at (pi/2 , pi/2), while in the electron doped compounds the band maxima locate at (pi, 0) and its equivalent points. The angle-resolved photoemission data for the quasiparticle dispersion of Sr_2CuO_2Cl_2 can be quantitatively reproduced using the one band t-t'-t"-J model with the three-site hopping term.