Origin of strong dispersion in Hubbard insulators

Article

关键词: J MODEL PARAMETERS;    SINGLE-PARTICLE;    CHARGE EXCITATIONS;    SPECTRAL-FUNCTION;    COPPER OXIDES;    SPIN POLARONS;    CUO2 PLANES;    HOLE;    ELECTRON;    CUPRATE;   

DOI  :  10.1103/PhysRevB.92.075119

来源: SCIE

【 摘 要 】

Using cluster perturbation theory, we explain the origin of the strongly dispersive feature found at high binding energy in the spectral function of the Hubbard model. By comparing the Hubbard and t-J-3s model spectra, we show that this dispersion does not originate from either coupling to spin fluctuations (proportional to J) or the free hopping (proportional to t). Instead, it should be attributed to a long-range, correlated hopping proportional to t(2)/U, which allows an effectively free motion of the hole within the same antiferromagnetic sublattice. This origin explains both the formation of the high-energy anomaly in the single-particle spectrum and the sensitivity of the high-binding-energy dispersion to the next-nearest-neighbor hopping t'.

【 授权许可】

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