Non-Fermi liquid behaviour of electrons in the half-filled honeycomb lattice (A renormalization group approach)

TL;DR

This paper uses renormalization group methods to show that electrons in a half-filled honeycomb lattice exhibit non-Fermi liquid behavior, characterized by anomalous dimensions and screening effects, similar to Luttinger liquids.

Contribution

It introduces a renormalizable quantum field theory for electrons in the honeycomb lattice and demonstrates non-Fermi liquid fixed point behavior using RG analysis.

Findings

Absence of quasiparticle pole in fermionic observables

Anomalous screening of Coulomb interactions

Infrared behavior similar to Luttinger liquids

Abstract

A system of electrons in the two-dimensional honeycomb lattice with Coulomb interactions is described by a renormalizable quantum field theory similar but not equal to QED_3. Renormalization group techniques are used to investigate the infrared behaviour of the system that flows to a fixed point with non-Fermi liquid characteristics. There are anomalous dimensions in the fermionic observables, no quasiparticle pole, and anomalous screening of the Coulomb interaction. These results are robust as the Fermi level is not changed by the interaction. The system resembles in the infrared the one-dimensional Luttinger liquid.