Dynamic response functions for the Holstein-Hubbard model

Article

关键词: NUMERICAL RENORMALIZATION-GROUP;    METAL-INSULATOR TRANSITIONS;    INFINITE DIMENSIONS;    ELECTRON-PHONON;    ATTRACTIVE HOLSTEIN;    FERMION SYSTEMS;    ANDERSON MODEL;    ENERGY;   

DOI  :  10.1103/PhysRevB.70.155103

来源: SCIE

【 摘 要 】

We present results on the dynamical correlation functions of the particle-hole symmetric Holstein-Hubbard model at zero temperature, calculated using the dynamical mean-field theory which is solved by the numerical renormalization group method. We clarify the competing influences of the electron-electron and electron-phonon interactions particularity at the different metal to insulator transitions. The Coulomb repulsion is found to dominate the behavior in large parts of the metallic regime. By suppressing charge fluctuations, it effectively decouples electrons from phonons. The phonon propagator shows a characteristic softening near the metal to bipolaronic transition but there is very little softening on the approach to the Mott transition.

【 授权许可】

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