Rigorous Born approximation and beyond for the spin-boson model
نویسندگان
چکیده
منابع مشابه
Boson-fermion Model beyond Mean-field Approximation
A model of hybridized bosons and fermions is studied beyond the mean field approximation. The divergent boson self-energy at zero temperature makes the Cooper pairing of fermions impossible. The frequency and momentum dependence of the self-energy and the condensation temperature T c of initially localized bosons are calculated analytically. The value of the boson condensation temperature T c i...
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In a recent paper [Alexandrov A S 1996 J. Phys.: Condens. Matter 8 6923–32; 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...
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ژورنال
عنوان ژورنال: Physical Review B
سال: 2005
ISSN: 1098-0121,1550-235X
DOI: 10.1103/physrevb.71.035318