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Comment on "Boson-fermion model beyond the mean-field approximation"

R. Friedberg·H. C. Ren·O. Tchernyshyov
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Abstract

In a recent paper [A.S.Alexandrov, J.Phys.:Condens.Matter 8, 6923 (1996); cond-mat/9603111], it has been suggested that there is no Cooper pairing in boson-fermion models of superconductivity. We show that this conjecture is based on an inconsistent approximation that violates an exact identity. Quite generally, the divergence of the fermion t-matrix (the Thouless criterion) is accompanied by the condensation of a boson mode.

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R. Friedberg, H. C. Ren, O. Tchernyshyov. 1997-05-09. Comment on "Boson-fermion model beyond the mean-field approximation". https://doi.org/10.1088/0953-8984%2F10%2F13%2F024

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