Abstract
We study the corrections to the Fermi energy induced by the interactions in a two-dimensional electron system, showing that it is attracted towards the Van Hove singularity for a certain range of doping levels. The scaling of the Fermi level allows to cure the infrared singularities left in the BCS channel after renormalization of the leading logarithm near the divergent density of states. A phase of d-wave superconductivity arises beyond the point of optimal doping corresponding to the peak of the superconducting instability. For lower doping levels, the condensation of particle-hole pairs due to the nesting of the saddle-points takes over, leading to the opening of a gap for quasiparticles in the neighborhood of the singular points.
- Received 31 July 2001
DOI:https://doi.org/10.1103/PhysRevB.67.054510
©2003 American Physical Society