SUPERCONDUCTIVITY INDICATIONS OF THE 2-CHAIN HUBBARD-MODEL DUE TO THE2-BAND EFFECT

Corroborating our assertion worked out in preceding papers that the tw o-chain Hubbard model has a superconducting (SC) parameter region, we report new results obtained by the Lanczos diagonalization method. The SC region indicated by SC pair correlation functions show the tendenc y to converge to a considerable definite region in the parameter space with increase of the system size. A certain SC correlation function r eveals that the SC order parameters pertinent to the two bands have di fferent signs. The SC pair operators at two rungs keep strong spatial correlation in our SC region in striking contrast to the non-SC region . Calculation of correlation exponent K-p allows us to get an SC param eter region which proves to be in a qualitative agreement with the abo ve-mentioned one.