Ultraviolet/infrared mixing in non-Fermi liquids

TL;DR

This paper investigates the complex UV/IR mixing phenomena in non-Fermi liquids with various Fermi surface dimensions, revealing how low-energy excitations and observables depend on Fermi surface size and identifying new fixed points.

Contribution

It introduces a unified framework for understanding UV/IR mixing in non-Fermi liquids across different Fermi surface geometries and finds perturbative fixed points influenced by both UV/IR mixing and interactions.

Findings

UV/IR mixing causes observables to depend on Fermi surface size.

Perturbative non-Fermi liquid fixed points are identified.

Dependence on Fermi surface dimension and co-dimension is characterized.

Abstract

We study low-energy effective field theories for non-Fermi liquids with Fermi surfaces of general dimensions and co-dimensions. When the dimension of Fermi surface is greater than one, low-energy particle-hole excitations remain strongly coupled with each other across the entire Fermi surface. In this case, even the observables that are local in the momentum space (such as the Green's functions) become dependent on the size of the Fermi surface in singular ways, resulting in an ultraviolet/infrared (UV/IR) mixing. By tuning the dimension and co-dimension of the Fermi surface independently, we find perturbative non-Fermi liquid fixed points controlled by both UV/IR mixing and interactions.