The green’s functions of superconductivity- A review
We present some basic Green’s functions of superconductivity, making emphasis on their geneology and analytic properties. From calculations, we note that the temperature dependence of the Green’s functions for fermionic (and bosonic) systems limits and defines the extent of their applications and results. Furthermore, the Gorkov interaction term of the four field fermion operators, is examined and interpreted in terms of the Landau condensate. Finally we show that the Gorkov interaction under a certain condition sustains superconductivity and spin density wave in the system.
KEYWORDS: Green’s functions, Bethe-Salpeter equation, Landau condensate, superconductivity, spin density wave.