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Local Moment Formation in the Periodic Anderson Model with Superconducting Correlations

M. A. N. Araujo·N. M. R. Peres·P. D. Sacramento
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Abstract

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 considerably stronger in the presence of superconducting correlations than in the non-superconducting system. Our study 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 one. 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 CeCu_2Si_2.

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M. A. N. Araujo, N. M. R. Peres, P. D. Sacramento. 2001-09-20. Local Moment Formation in the Periodic Anderson Model with Superconducting Correlations. https://doi.org/10.1103/physrevb.65.012503

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