Nematic Quantum Criticality Without Order

TL;DR

This paper investigates a two-dimensional Fermi system where nematic order can be suppressed by fluctuations, leading to a quantum critical point without an ordered phase, using a non-perturbative renormalization-group approach.

Contribution

It demonstrates that order-parameter fluctuations can eliminate nematic order at zero temperature, revealing a quantum critical point without an adjacent ordered phase.

Findings

Order-parameter fluctuations suppress nematic order at zero temperature.

A quantum critical point exists without an ordered phase.

Quantum critical behavior arises in the disordered phase.

Abstract

We consider a two-dimensional interacting Fermi system which displays a nematic phase within mean-field theory. The system is analyzed using a non-perturbative renormalization-group scheme. We find that order-parameter fluctuations can suppress the nematic order obtained in mean-field theory even at zero temperature. For a suitable choice of parameters a quantum critical point surrounded by a disordered phase can be realized, giving rise to quantum critical behavior in the absence of an ordered regime in the phase diagram.