EVOLUTION OF HOLE AND MAGNON SPECTRA OF THE 2-DIMENSIONAL T-J MODEL WITH DOPING

Hole and magnon spectral functions of the two-dimensional t-J model ar e self-consistently calculated for hole concentrations x less than or similar to 0.3. The employed system of Dyson's equations was obtained with the use of the Born and spin-wave approximations. It is shown tha t near x = 0.05 the hole spectrum is changed drastically acquiring fea tures of a wealrly correlated spectrum. This change is accompanied by a substantial decrease of the carrier effective mass and by entering t he chemical potential mu into a sharp maximum of the density of states . With increasing a the maximum moves together with mu up to x approxi mate to 0.15 and then lags behind. This concentration is also distingu ished by the facts that the Fermi surface becomes a simply connected s urface and overdamped magnons, which appear at x approximate to 0.02, occupy the widest region in kappa space. Besides, here usual magnons h ave the smallest limiting frequency which is approximately three times smaller than the initial one. Significant deviations from the normal Fermi liquid, which partly resemble marginal Fermi liquid, are observe d for x greater than or similar to 0.05.