Hole propagation in correlated spin systems

An approximation method is presented for the calculation of the Green's function for a single hole moving in a correlated spin background. General formulas are obtained for calculating the moments of the Green's function, generalizing the Brinkman-Rice method to a general spin state. Numerical results are presented for a one-dimensional Gutzwiller resonating-valence-bond (RVB) state. In the two-dimensional case, the bandwidth is derived. The kinetic energy of a single hole in a correlated antiferromagnet or Gutzwiller RVB state is higher than in a N\'eel antiferromagnet.