Parquet solution for a flat Fermi surface
Abstract
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-Tc superconductors. In the framework of the parquet approximation, we classify possible instabilities and derive renormalization-group equations that determine the evolution of corresponding susceptibilities with decreasing temperature. Numerical solutions of the parquet equations are found to be in qualitative agreement with a ladder approximation. For the repulsive Hubbard interaction, the antiferromagnetic (spin-density-wave) instability dominates, but when the Fermi surface is not perfectly flat, the d-wave superconducting instability takes over.
- Publication:
-
Physical Review B
- Pub Date:
- February 1997
- DOI:
- 10.1103/PhysRevB.55.3200
- arXiv:
- arXiv:cond-mat/9609118
- Bibcode:
- 1997PhRvB..55.3200Z
- Keywords:
-
- Condensed Matter
- E-Print:
- REVTeX, 36 pages, 20 ps figures inserted via psfig. Submitted to Phys. Rev. B