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Two Anderson impurities in the framework of the non‐crossing approximation: Spectral functions and spin correlations
Author(s) -
Schiller A.,
Zevin V.
Publication year - 1996
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.2065080406
Subject(s) - degenerate energy levels , impurity , isotropy , antiferromagnetism , physics , anderson impurity model , spin (aerodynamics) , condensed matter physics , ground state , quenching (fluorescence) , quantum mechanics , thermodynamics , fluorescence
Using a novel slave boson mapping, which was recently proposed by us for two Anderson impurities embedded in a metal, we present here spectral functions for all pseudoparticles involved in the mapping. These were numerically calculated in the framework of the Non‐Crossing Approximation for different temperatures and inter‐impurity distances, both for the degenerate ( N f = 6) and nondegenerate ( N f = 2) models. For the nondegenerate case, temperature dependencies of the partial occupancies and the spin‐spin correlation function suggest that an antiferromagnetic (AFM)‐like ground state is formed at suitable inter‐impurity separation. By contrast, Kondo quenching of the impurity moments takes place for the isotropic N f = 6 case even when a direct AFM interaction is introduced in order to amplify the indirect (inherent) one. Numerical calculations are in agreement with our previous prediction [Phys. Rev. B 47, 14,297 (1993)] that no AFM‐like ground state can appear for two isotropic degenerate impurities.