VIOLATION OF LUTTINGERS THEOREM IN THE 2-DIMENSIONAL T-J MODEL

We have calculated the high temperature series for the momentum distri bution function n(k) of the 2D t-J model to twelfth order in inverse t emperature. By extrapolating the series to T = 0.2J we searched for a Fermi surface of the 2D t-J model. We find that three criteria used fo r estimating the location of a Fermi surface violate Luttinger's theor em, implying that the t-J model does not have an adiabatic connection to a noninteracting model.