Vn. Muthukumar et al., SUPERCONDUCTIVITY FROM A NON-FERMI-LIQUID - A GINZBURG-LANDAU APPROACH, Physical review. B, Condensed matter, 52(13), 1995, pp. 9647-9653
We present a microscopic derivation of the Ginzburg-Landau free-energy
functional starting from a non-Fermi-liquid ground state characterize
d by a single particle Green's function g(0)(k,omega) =omega(c)(-alpha
)/(i omega-epsilon(k))(1-alpha). We assume a BCS-like pairing interact
ion and obtain analytical expressions for the Ginzburg-Landau coeffici
ents a (T) and b as functions of the scaling exponent alpha. We show h
ow a nonvanishing value of the exponent alpha (which leads to a breakd
own of Fermi-liquid theory in the normal state) yields qualitatively a
nd quantitatively different results in the superconducting state.