ANOMALOUS SPIN AND CHARGE DYNAMICS OF THE T-J MODEL AT LOW DOPING

We present an exact diagonalization study of the dynamical spin and density correlation functions in small clusters of 2D t-J model for hole dopings ≤25%. Both correlation functions show a remarkably regular, but very different, scaling with both hole density ρh and parameters t and J. The density correlation function is most consistent with that of condensed bosons in a band of width ∼t, the spin correlation function with that of fermions in a band of width ∼J. We show that the familiar spin bag scenario explains these results in a natural way. © 1995 The American Physical Society.