RESONANT IMPURITY SCATTERING IN A STRONGLY CORRELATED ELECTRON MODEL

Scattering by a single impurity introduced in a strongly correlated el ectronic system is studied by exact diagonalization of small clusters. It is shown that an inert site which is spinless and unable to accomm odate holes can give rise to strong resonant scattering. A calculation of the local density of state reveals that, for increasing antiferrom agnetic exchange coupling, d-, s-, and p-wave symmetry bound states in which a mobile hole is trapped by the impurity potential induced by a local distortion of the antiferromagnetic background successively pul l out from the continuum.