Electrons with alternating on-site and correlated hopping interactions


  • Research performed within the program of the Sonderforschungsbereich 341 supported by the Deutsche Forschungsgemeinschaft.


The 1 D one-band Hubbard model with different repulsive on-site interactions on even (U+V > 0) and odd (U-V > 0) sites, supplemented by the correlated-hopping term (t* > 0), describing the modification of the electron hopping by the presence of other particles on the sites, is considered as a 1 D model for CuO systems. The ground state phase diagram is studied within the framework of the bosonization technique and renormalization group analysis valid for weak coupling. Depending on the choice of model parameters, the following sequences of phase transitions with increasing bandfilling occur: 1) metal-insulator-metal (for t* ⩽ U/4); 2) metal-insulator-metal-superconductor equation imagemetal-superconductor-metal-insulator-metal-superconductor equation imagemetal-superconductor equation image.