Possibility of metal-insulator transitions in hole-doped cuprates induced by strong electron correlation, disorder and extrinsic carrier self-trapping

The adequate theoretical approaches to the correlation- and disorder-induced metal-insulator transitions (MITs) (i.e., Mott and Anderson MITs) and the new MITs caused by the extrinsic self-trapping of carriers in hole-doped cuprates are developed. Using these approaches we obtain the appropriate criteria for the Mott and Anderson MITs driven by the strong electron correlation (in a narrow tight-binding impurity band) and disorder (in the special distribution of dopants), and the new MITs driven by the strong carrier-phonon-dopant (or impurity) interactions which lead to the self-trapping of carriers near dopants and the formation of large extrinsic (bi)polarons. The relevance of the results to high-Tc cuprates is discussed