Ferromagnetism in the one-dimensional Hubbard model with orbital degeneracy: From low to high electron density

Article

关键词: METAL-INSULATOR-TRANSITION;    GROUND-STATES;    MOMENTUM DISTRIBUTION;    BAND MODEL;    SYSTEMS;    EXCHANGE;   

DOI  :  10.1103/PhysRevB.65.224403

来源: SCIE

【 摘 要 】

We studied ferromagnetism in the one-dimensional Hubbard model with doubly degenerate atomic orbitals by means of the density-matrix renormalization-group method and obtained the ground-state phase diagrams. It was found that ferromagnetism is stable from low to high (01), the phase diagram of the ferromagnetic phase is similar to that obtained in infinite dimensions. In this case, the double exchange mechanism is operative for stabilizing the ferromagnetic order and this long-range order is robust against variation of the band dispersion. A partially polarized state appears in the density region 1.68less than or similar tonless than or similar to1.75 and phase separation occurs for n just below the half-filling (n=2).

【 授权许可】

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