Non-Fermi Liquid Behaviour in d = 2 Spatial Dimension

TL;DR

This paper investigates a two-dimensional fermionic system with singular interactions, demonstrating that strong coupling effects lead to a breakdown of traditional Fermi liquid theory through renormalization group analysis.

Contribution

It introduces a regularized boson-fermion model in 2D and shows the emergence of non-Fermi liquid behavior via non-perturbative renormalization group methods.

Findings

Interaction singularity in 2D affects quasiparticle behavior

Model exhibits non-perturbative regime where Fermi liquid theory fails

Renormalization group analysis reveals non-Fermi liquid phase

Abstract

We consider a local effective model for fermionic low lying excitations in a metal. Introducing a boson auxiliary field and taking into account that the most significant interactions between quasiparticles arise for those which are near a given point on the Fermi surface, we find that the effective boson-fermion interaction is singular for a spatial dimension d=2. We regularize the theory and apply the renormalization group method. As we vary the coupling constant as a function of an energy scale parameter we show that the model undergoes a non-perturbative regime in which the Fermi liquid theory is no longer valid.