SPIN-POLARON WAVE-FUNCTION FOR A SINGLE HOLE IN AN ANTIFERROMAGNET

The wave function of a single hole moving in a two-dimensional antifer romagnet is derived from the Green's function obtained within self-con sistent Born approximation. Starting from the wave function various co rrelation functions which characterize the distortion of the antiferro magnetic background around the hole can be calculated. Both the t-J an d the t-J(z) model are studied. Whereas for the t - J(z) model these p erturbations are essentially isotropic and decay exponentially with th e distance from the hole, their decay in the t-J model has power-law f orm. Moreover the correlation functions in the t - J model are are hig hly anisotropic and depend strongly on the momentum of the quasipartic le.