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arXiv · 0906.2752

Kondo--attractive-Hubbard model for the ordering of local magnetic moments in superconductors

P. R. Bertussi·A. L. Malvezzi·T. Paiva·R. R. dos Santos
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Abstract

We consider local magnetic moments coupled to conduction electrons with on-site attraction, in order to discuss the interplay between pairing and magnetic order. We probe the ground state properties of this model on a one-dimensional lattice through pair binding energies and several correlation functions, calculated by means of density-matrix renormalization group. A phase diagram is obtained (for fixed electron density 1/3), from which we infer that coexistence between magnetic order and superconductivity is robust, at the expense of a continuous distortion of the magnetic arrangement of the local moments, as evidenced by a strong dependence of the characteristic wave vector k* with the coupling constants. This allows us to understand some trends of the coexistence, such as the influence of the rare earth on k*, as observed experimentally in the borocarbides.

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P. R. Bertussi, A. L. Malvezzi, T. Paiva, R. R. dos Santos. 2009-06-15. Kondo--attractive-Hubbard model for the ordering of local magnetic moments in superconductors. https://doi.org/10.1103/physrevb.79.220513

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