Parquet solution for a flat Fermi surface
Parquet solution for a flat Fermi surface
We study instabilities occurring in the electron system whose Fermi surface has flat regions on its opposite sides. Such a Fermi surface resembles Fermi surfaces of some high-${\mathrm{T}}_{\mathrm{c}}$ superconductors. In the framework of the parquet approximation, we classify possible instabilities and derive renormalization-group equations that determine the evolution of corresponding …