Periodic Anderson model with correlated conduction electrons

Article

关键词: MEAN-FIELD THEORY;    DILUTE MAGNETIC-ALLOYS;    HEAVY FERMION SYSTEMS;    LARGE-N EXPANSION;    INFINITE DIMENSIONS;    HUBBARD-MODEL;    LUTTINGER LIQUID;    GAP FORMATION;    IMPURITY;    LATTICE;   

DOI  :  10.1103/PhysRevB.56.6559

来源: SCIE

【 摘 要 】

We investigate a periodic Anderson model with interacting conduction electrons which are described by a Hubbard-type interaction of strength U-c. Within dynamical mean-field theory the total Hamiltonian is mapped onto an impurity model, which is solved by an extended noncrossing approximation. We consider the particle-hole symmetric case at half filling. Similar to the case U-c=0, the low-energy behavior of the conduction electrons at high temperatures is essentially unaffected by the f electrons and for small U-c a quasiparticle peak corresponding to the Hubbard model evolves first. These quasiparticles screen the f moments when the temperature is reduced further, and the system turns into an insulator with a tiny gap and flat bands. The formation of the quasiparticle peak is impeded by increasing either U-c or the c-f hybridization. Nevertheless almost dispersionless bands emerge at low temperature with an increased gap, even in the case of initially insulating host electrons. The size of the gap in the one-particle spectral density at low temperatures provides an estimate for the low-energy scale and increases as U-c increases.

【 授权许可】

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