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arXiv · 0803.2590

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

T. Shirakawa·S. Nishimoto·Y. Ohta
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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.

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T. Shirakawa, S. Nishimoto, Y. Ohta. 2008-03-18. Superconductivity in a model of two Hubbard chains coupled with ferromagnetic exchange interaction. https://doi.org/10.1103/physrevb.77.224510

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