Superconductivity and non-Fermi liquid behavior near a nematic quantum critical point

TL;DR

This study uses quantum Monte Carlo simulations to explore how nematic quantum criticality influences superconductivity and non-Fermi liquid behavior in a lattice model of itinerant electrons, revealing a broad superconducting dome and anomalous metallic properties.

Contribution

It provides the first unbiased numerical evidence linking nematic quantum critical fluctuations to superconductivity and non-Fermi liquid behavior in a lattice model.

Findings

Superconductivity forms a broad dome around the nematic quantum critical point.

Above Tc, the system exhibits non-Fermi liquid behavior with a nodal-anti nodal dichotomy.

Critical fluctuations significantly alter low-frequency optical conductivity, resembling 'bad metal' behavior.

Abstract

Using determinantal quantum Monte Carlo, we compute the properties of a lattice model with spin $\frac 1 2$ itinerant electrons tuned through a quantum phase transition to an Ising nematic phase. The nematic fluctuations induce superconductivity with a broad dome in the superconducting $T_c$ enclosing the nematic quantum critical point. For temperatures above $T_c$, we see strikingly non-Fermi liquid behavior, including a "nodal - anti nodal dichotomy" reminiscent of that seen in several transition metal oxides. In addition, the critical fluctuations have a strong effect on the low frequency optical conductivity, resulting in behavior consistent with "bad metal" phenomenology.