Lattice models for non-Fermi liquid metals

TL;DR

This paper introduces two 2D lattice models that exhibit non-Fermi liquid metallic phases, characterized by fractionalized quasiparticles coupled to a U(1) gauge field, expanding understanding of exotic metallic states.

Contribution

The paper presents two exactly solvable lattice models demonstrating non-Fermi liquid phases with fractionalized quasiparticles, one with fermions and the other with bosons, including a Bose metal and a spin liquid.

Findings

Demonstrates electron-based non-Fermi liquid phase.

Provides a bosonic model for a Bose metal.

Offers a critical U(1) spin liquid example.

Abstract

We present two 2D lattice models with non-Fermi liquid metallic phases. We show that the low energy physics of these models is exactly described by a Fermi sea of fractionalized quasiparticles coupled to a fluctuating U(1) gauge field. In the first model, the underlying degrees of freedom are spin 1/2 fermions. This model demonstrates that electrons can in principle give rise to non-Fermi liquid metallic phases. In the second model, the underlying degrees of freedom are spinless bosons. This model provides a concrete example of a (non-Fermi liquid) Bose metal. With little modification, it also gives an example of a critical U(1) symmetric spin liquid.