Generalized Pomeranchuk instabilities in graphene

TL;DR

This paper investigates Pomeranchuk instabilities in graphene's Fermi liquid, revealing stability near half filling and instability near Van Hove filling, using a generalized method to map the phase diagram.

Contribution

It introduces a generalized Pomeranchuk method to analyze instabilities in graphene, providing a comprehensive phase diagram across various fillings and interactions.

Findings

Instability region near Van Hove filling with repulsive interactions.

Fermi liquid stability near half filling.

Method enables complete phase diagram mapping.

Abstract

We study the presence of Pomeranchuk instabilities induced by interactions on a Fermi liquid description of a graphene layer. Using a recently developed generalization of Pomeranchuk method we present a phase diagram in the space of fillings versus on-site and nearest neighbors interactions. Interestingly, we find that for both interactions being repulsive an instability region exists near the Van Hove filling, in agreement with earlier theoretical work. In contrast, near half filling, the Fermi liquid behavior appears to be stable, in agreement with theoretical results and experimental findings using ARPES. The method allows for a description of the complete phase diagram for arbitrary filling.