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Magnetic impurities in small metal clusters
Author(s) -
Pastor G.M.
Publication year - 2005
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.200510153
Subject(s) - josephson effect , physics , condensed matter physics , impurity , quantum , hubbard model , quantum phase transition , phase (matter) , quantum mechanics , superconductivity
Dedicated to Bernhard Mühlschlegel on the occasion of his 80th birthdayMagnetic impurities in small metallic clusters are investigated in the framework of the Anderson model by using exact diagonalization and geometry optimization methods.The singlet‐triplet spin gap Δ E shows a remarkable dependence as a function of band‐filling, cluster structure, and impurity position that can be interpreted in terms of the environment‐specific conduction‐electron spectrum. The low‐energy spin excitations involve similar energies as isomerizations. Interesting correlations between cluster structure and magnetic behavior are revealed. Finite‐temperature properties such as specific heat, effective impurity moment, and magnetic susceptibility are calculated exactly in the canonical ensemble. A finite‐size equivalent of the Kondo effect is identified and its structural dependence is discussed.