THE INSTABILITY OF A 2D ELECTRON-GAS NEAR THE CRITICAL DENSITY FOR A WIGNER POLARON CRYSTAL GIVING THE QUANTUM STATE OF CUPRATE SUPERCONDUCTORS

Experimental evidence that the metallic phase in the Bi2212 high T(c) cuprate superconductors results from an instability of a 2D-electron gas with density lower or larger than the critical density pc for the formation of a generalized Wigner polaronic crystal is reported. The critical density pc is obtained from rho(c) = 1/S(p) where S(p) is the measured area of condensed polarons. We have found that the 2D-electron gas at charge densities rho not-equal rho(c) in the range rho(c)/22 supports the model for the pairing mechanism.