Spatial distribution of mobile holes in the t-J model.

Abstract

We have calculated the hole-hole correlation function for two holes doped into a 5= 1/2 antiferromagnetic insulator described by the t Jmodel o-n a 16-site +8X ~32 lattice and a 24-site ~18X ~32 lattice using an exact diagonalization technique. We predict that the carriers described by this model, in the parameter range relevant to Cu02 planes, tend to stay as far apart as possible. This result is in direct contradiction to previously published exact diagonalization data [e.g., D. Poilblanc, Phys. Rev. B 49, 1477 (1994)].We suggest that if the carriers do tend to stay as far apart from one another as possible, then the electron momentum distribution function shows evidence for hole pockets at k=(~ m/2, ~ 7t/2), consistent with many recent studies of these models, including recent photoemission work.