Pairing interaction near a nematic QCP of a 3-band CuO$_2$ model

TL;DR

This paper investigates how nematic fluctuations near a quantum critical point influence the $d$-wave pairing strength and gap structure in a CuO$_2$ model, revealing the role of higher order harmonics in the pairing interaction.

Contribution

It provides a detailed calculation of the $k$ dependence of the superconducting gap and the influence of nematic fluctuations near a QCP in a three-band CuO$_2$ model.

Findings

Higher order $d$-wave harmonics affect the gap structure.

Nematic fluctuations enhance pairing near the QCP.

The gap function's $k$ dependence reflects the longer-range pairing interaction.

Abstract

Here we calculate the strength of the $d$-wave pairing and the $k$ dependence of the gap function associated with the nematic fluctuations of a CuO$_2$ model as the doping $p$ approaches a quantum critical point. Higher order $d$-wave harmonics contribute to the $k$ dependence of the resulting superconducting gap function reflecting the longer range nature of the nematic pairing interaction.