TY - JOUR
T1 - New model for the mixed-valence phenomenon in rare-earth materials
AU - Haldane, F. D.M.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 1977
Y1 - 1977
N2 - A model of a single rare-earth atom in a transition metal is derived, and terms describing screening of charge fluctuations in the resonant l=3 scattering channels by the l=2 channels are included. Using the Tomonaga approximation, in which charge fluctuations are represented by bosons, the screening channels are replaced by a boson field, and the model takes on a particularly simple form, the Anderson model of a magnetic impurity, now coupled to the boson field. The mean-field theory of this model suggests that, unlike in the original Anderson model, the impurity can be in a state of slowly fluctuating valence, which we identify with the mixed-valence phenomenon in certain rare-earth materials. These results suggest that the mixed-valence effect may be purely electronic in origin.
AB - A model of a single rare-earth atom in a transition metal is derived, and terms describing screening of charge fluctuations in the resonant l=3 scattering channels by the l=2 channels are included. Using the Tomonaga approximation, in which charge fluctuations are represented by bosons, the screening channels are replaced by a boson field, and the model takes on a particularly simple form, the Anderson model of a magnetic impurity, now coupled to the boson field. The mean-field theory of this model suggests that, unlike in the original Anderson model, the impurity can be in a state of slowly fluctuating valence, which we identify with the mixed-valence phenomenon in certain rare-earth materials. These results suggest that the mixed-valence effect may be purely electronic in origin.
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U2 - 10.1103/PhysRevB.15.2477
DO - 10.1103/PhysRevB.15.2477
M3 - Article
AN - SCOPUS:25044439498
VL - 15
SP - 2477
EP - 2484
JO - Physical Review B
JF - Physical Review B
SN - 0163-1829
IS - 5
ER -