Local-moment formation in the periodic Anderson model with superconducting correlations

Article

关键词: HEAVY-FERMION SYSTEMS;    LATTICE MODEL;    MIXED-VALENCE;    UPD2AL3;    METALS;    ANTIFERROMAGNETISM;    FLUCTUATIONS;    COEXISTENCE;    MAGNETISM;    CECU2SI2;   

DOI  :  10.1103/PhysRevB.65.012503

来源: SCIE

【 摘 要 】

We study local-moment formation in the presence of superconducting correlations among the f electrons in the periodic Anderson model. Local moments form if the Coulomb interaction U > U-cr. We find that U-cr is considerable stronger in the presence of superconducting correlations than in the nonsuperconducting system. Our studs is done for various values of the f-level energy and electronic density. The smallest critical U-cr values occur for the case where the number of f electrons per site is equal to 1. In the presence of d-wave superconducting correlations we find that local-moment formation presents a quantum phase transition as function of pressure. This quantum phase transition separates a region where local moments and d-wave superconductivity coexist from another region characterized by a superconducting ground state with no local moments. We discuss the possible relevance of these results to experimental studies of the competition between magnetic order and superconductivity in CeCu2Si2.

【 授权许可】

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