M. Acquarone et G. Rebecchi, SCREENED CORRELATION AND METAL-INSULATOR-TRANSITION IN LA2-DELTA-SR-DELTA-CUO4 AND Y1-DELTA-CA-DELTA-TIO3, Physica. C, Superconductivity, 235, 1994, pp. 1301-1302
The impossibility to explain doping- dependent delocalization transiti
ons in strongly correlated system as due to the renormalization of the
charge excitation energy, suggest that they might be due to the colla
pse of the spin-polarons.