Electron-momentum distribution function and spectral function in thet-Jmodel

The momentum distribution function and electron spectral function for mobile holes in an antiferromagnet as described by the t-J model are discussed. The calculations are done using a trial wave function for the coherent motion of an individual hole based on a string picture. To discuss finite concentrations, the rigid-band approximation is assumed to be valid. Despite this both quantities considered are qualitatively similar to what one would expect for weakly interacting particles occupying the tight-binding band calculated from the hopping term in the Hamiltonian.