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arXiv 0710.2274cond-mat.str-el
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一维次近邻跳跃哈伯德模型的Phase diagram

Phase diagram of the one-dimensional Hubbard model with next-nearest-neighbor hopping

S. Nishimoto, K. Sano, Y. Ohta

摘要:

利用密度矩阵重整化群(DMRG)方法和Hartree-Fock近似,研究了具有最近邻和次最近邻跳跃积分的一维哈伯德模型.基于自旋能隙、总自旋量子数和Tomonaga-Luttinger-liquid参数的计算结果,我们确定了该模型在全填充和宽参数区的基态相图.我们表明,在弱耦合制度的自旋带隙的液相预测在该地区有四个费米点,自旋间隙消失在一个实质性的区域中的强耦合制度。值得注意的是,各种各样的相,如顺磁性金属相,自旋带隙的液相,单线态和三线态超导相,和完全极化的铁磁相,出现在这样一个简单的模型中的强耦合制度。

英文摘要:

We study the one-dimensional Hubbard model with nearest-neighbor and next-nearest-neighbor hopping integrals by using the density-matrix renormalization group (DMRG) method and Hartree-Fock approximation. Based on the calculated results for the spin gap, total-spin quantum number, and Tomonaga-Luttinger-liquid parameter, we determine the ground-state phase diagram of the model in the entire filling and wide parameter region. We show that, in contrast to the weak-coupling regime where a spin-gapped liquid phase is predicted in the region with four Fermi points, the spin gap vanishes in a substantial region in the strong-coupling regime. It is remarkable that a large variety of phases, such as the paramagnetic metallic phase, spin-gapped liquid phase, singlet and triplet superconducting phases, and fully polarized ferromagnetic phase, appear in such a simple model in the strong-coupling regime.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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