Electron self-energy from quantum charge fluctuations in the layered t-J model with long-range Coulomb interaction

Article

关键词: DIMENSIONAL FERMI-SURFACE;    COLLECTIVE EXCITATIONS;    SLAVE-PARTICLE;    SUPERCONDUCTIVITY;    LIQUID;    STATES;    GAS;    RENORMALIZATION;    INSTABILITIES;    PHOTOEMISSION;   

DOI  :  10.1103/PhysRevB.104.045141

来源: SCIE

【 摘 要 】

Employing a large-N scheme of the layered t-J model with the long-range Coulomb interaction, which captures the fine details of the charge excitation spectra recently observed in cuprate superconductors, we explore the role of charge fluctuations on the electron self-energy. We fix the temperature at zero and focus on quantum charge fluctuations. We find a pronounced asymmetry of the imaginary part of the self-energy Im Sigma(k, omega) with respect to omega = 0, which is driven by strong electron correlation effects. The quasiparticle weight is reduced dramatically, which occurs almost isotropically along the Fermi surface. Concomitantly, an incoherent band and a sharp side band are generated and acquire sizable spectral weight. All these features are driven by the usual on-site charge fluctuations, which are realized in a rather high-energy region and yield plasmon excitations. On the other hand, the low-energy region with the scale of the superexchange interaction J is dominated by bond-charge fluctuations. Surprisingly, compared with the effect of on-site charge fluctuations, their effect on the electron self-energy is much weaker, even if the system approaches close to bond-charge instabilities. Furthermore, quantum charge dynamics does not produce a clear kink nor a pseudogap in the electron dispersion.

【 授权许可】

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