2008/10/14 by S. Miyashita, Satoshi Miyashita, Y. Yamashita +7
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1088/1742-6596/150/4/042128
4 pages, 2 figures, Proceedings of LT25
arxiv created 2008/10/14 · openalex publication_date 2009/03/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We investigate the ground-state properties of the one-dimensional two-band Hubbard model with different bandwidths. The density-matrix renormalization group method is applied to calculate the averaged electron occupancies n as a function of the chemical potential μ. Both at quarter and half fillings, "charge plateaux" appear in the n-μ plot, where dμ/dn diverges and the Mott insulating states are realized. To see how the orbital polarization in the one-quarter charge plateau develops, we apply the second-order perturbation theory from the strong-coupling limit at quarter filling. The resultant Kugel-Khomskii spin-orbital model includes a magnetic field coupled to orbital pseudo-spins. This field originates from the discrepancy between the two bandwidths and leads to a finite orbital pseudo-spin magnetization.