High-Doping Regime in a Planar Model for Strongly Correlated Electrons

The exact diagonalization study of the effective single-band ( t - J ) model for strongly correlated electrons in a layered system of 16 cells, has been extended to a larger number of holes, i.e. up to N h = 4. A higher concentration of holes definitely reduces the range of antiferromagnetic correlations and the correlated state behaves more as a dilute system of correlated fermions. Still the hole-density correlations and moreover the four-point density correlations reveal a tendency to pairing in the intermediate regime of exchange couplings J / t , in contrast to the formation of droplets at larger J / t .