Superconducting correlations in the asymmetric Hubbard model

K. P. Jain, R. Ramakumar, C. C. Chancey

Liliana Arrachea, Armando A. Aligia, Eduardo R. Gagliano

E.S. Caixeiro, A. Troper

Zbigniew Domański, R. Lemański, Gábor Fáth

An interaction between two heavy electrons mediated by two light electrons is investigated within the asymmetric Hubbard model on a square cluster with sites. The pair correlation function describing the probabilities of all relative positions of the heavy electrons is calculated by an approximative method. An effective attraction is found to exist in a certain range of model parameters.

Yoshihiro Asai

We have studied the superconducting, magnetic, and charge correlation functions and the spin excitation spectrum in the doped two-chain Hubbard model by projector Monte Carlo and Lanczos diagonalization methods. The exponent of the interchain singlet superconducting correlation function, \ensuremath{\gamma}, is found to be close to 2.0 as long as two distinct noninteracting bands cross the Fermi level. Magnetic and charge correlation functions decay more rapidly than or as fast as the interchain singlet superconducting correlation function along the chains. The superconducting correlation in the doped two-chain Hubbard model is the most long-range correlation studied here. Implications of the results for the possible universality class of the doped two-chain Hubbard model are discussed.

Ehsan Khatami, Richard T. Scalettar, Rajiv R. P. Singh