| Abstract: | The 1D system of correlated electrons characterized in addition to the usual on-site (U) and nearest-neighbour (V) repulsion by a correlated-hopping term (t*) is considered. The ground state phase diagram is studied within the framework of the weak-coupling continuum-limit approach. At filling v the effective interaction originating from the correlated-hopping term which appears in the continuum-limit theory is given by t* cos (πv). Being repulsive for v < 1/2 and attractive for v > 1/2, this interaction leads to a characteristic band-filling dependence of the phase diagram of the system. For v ≠ 1/2, depending on the relation between the bare values of the coupling constants (U, V, t* cos (π v)) and, hence, on the band-filling, the system shows three different phases in the infrared limit: a Luttinger metal, a nonmagnetic metal and a singlet superconducting phase. For v = 1/2, the correlated-hopping interaction is dynamically trivial, leading only to a renormalization of the oneelectron hopping amplitude and the phase diagram of the model coincides with that of the extended Hubbard model. |
