Superconductivity arising from an incoherent metal in a two-dimensional Yukawa Sachdev-Ye-Kitaev model

Recent years have seen growing interest in superconductivity that emerges from incoherent metals. Building on prior large N theory of critical Fermi surfaces[1], we present a lattice model with real Yukawa couplings random in both flavor and position space. Our study includes the numerical solutions of the saddle point equations and the corresponding Large-N phase diagram. There is a pairing instability at low energies, and we numerically calculate the superconducting transition temperature, T_sc. Additionally, we delve into properties such as spectral functions, optical conductivity, and superfluid density at the onset of superconductivity. Our discussion concludes with an exploration of the relationship between superconductivity and "Planckian" normal state resistivity.

[1] Large-N theory of critical Fermi surfaces, I. Esterlis et al., Phys. Rev. B 103, 235129 (2021)