INDICATIONS OF SPIN-CHARGE SEPARATION IN THE 2-DIMENSIONAL T-J MODEL

We have calculated the high temperature expansion for the density correlation function N(q) of the two-dimensional t-J model. On extrapolation by Pade approximants to low temperatures we find that N(q) has 2k(F)SF as a characteristic wave vector. Previous studies have shown that n(k) has a steplike feature at k(F) and S(q) has 2k(F) as a characteristic wave vector. Here k(F) and k(F)SF are the Fermi wave vectors of the nearest-neighbor square lattice tight-binding and spinless fermion models, respectively. By comparison to known results for one dimension this suggests spin-charge separation in the two-dimensional t-J model.