Role of correlated hopping in the many-body physics of flat-band systems: Nagaoka ferromagnetism

Article

关键词: PHASE-SEPARATION INSTABILITY;    GENERALIZED HUBBARD-MODEL;    ELECTRON-ENERGY SPECTRUM;    EXCHANGE INTERACTIONS;    POLAR MODEL;    NARROW;    SPIN;    CRYSTAL;    QUANTUM;    STATES;   

DOI  :  10.1103/PhysRevB.106.L041104

来源: SCIE

【 摘 要 】

In narrow-band systems, correlated contribution to effective hopping becomes important, and one needs to carefully consider three types of hopping processes: between doubly and singly occupied sites, between singly occupied and empty sites, and between doubly occupied and empty or two singly occupied sites. All three hopping parameters cannot vanish simultaneously, and one should specify for which of these processes the band becomes flat. By means of exact diagonalization of finite systems we demonstrate that three hoppings play qualitatively different roles in many-body effects, in particular, in the formation of half-metallic ferromagnetic

【 授权许可】

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