Superconductivity in a model of two Hubbard chains coupled with ferromagnetic exchange interaction

Abstract

We study the ground-state properties of the double-chain Hubbard model coupled with ferromagnetic exchange interaction by using the weak-coupling theory, density-matrix renormalization group technique, and Lanczos exact-diagonalization method. We determine the ground-state phase diagram in the parameter space of the ferromagnetic exchange interaction and band filling. We find that, in high electron density regime, the spin gap opens and the spin-singlet $d_{xy}$-wave-like pairing correlation is most dominant, whereas in low electron density regime, the fully-polarized ferromagnetic state is stabilized where the spin-triplet $p_y$-wave-like pairing correlation is most dominant.

11 pages, 10 figures

References in corpus (4)

• Tomonaga-Luttinger parameters for doped Mott insulators
• Phase diagram of the one-dimensional Hubbard model with next-nearest-neighbor hopping
• Ring Exchange Mechanism for Triplet Superconductivity in a Two-Chain Hubbard Model: Possible Relevance to Bechgaard Salts
• Charge and spin excitation spectra in the one-dimensional Hubbard model with next-nearest-neighbor hopping