TEMPERATURE AND DOPING DEPENDENCE OF THE QUASI-PARTICLE SPECTRUM FOR HOLES IN THE SPIN-POLARON MODEL OF COPPER OXIDES

The spectral function and the momentum distribution for holes in an an tiferromagnet are calculated on the basis of the t-J model in a slave- fermion representation. The self-consistent Born approximation for the two-time Green's function is used to study the temperature and doping (delta) dependence of the self-energy operator. The numerical calcula tions show a weak concentration and temperature dependence of the spec tral function (quasiparticle hole spectrum) while the momentum distrib ution function changes dramatically with increasing temperature for T > T(d) with T(d) congruent-to Jdelta.