Dynamic cluster quantum Monte Carlo simulations of a two-dimensional Hubbard model with stripe-like charge density wave modulations: Interplay between inhomogeneity and superconductivity

TL;DR

This study uses dynamic cluster quantum Monte Carlo simulations to explore how stripe-like charge density wave modulations influence superconductivity in a doped two-dimensional Hubbard model, revealing enhanced pairing correlations and critical temperature.

Contribution

It demonstrates that stripe-like charge modulations can enhance superconductivity in the Hubbard model, highlighting the interplay between inhomogeneity and pairing mechanisms.

Findings

Increased pairing correlations with larger modulation length-scales.

Enhanced critical temperature due to charge density wave modulations.

Optimal superconductivity occurs at moderate modulation strength.

Abstract

Using dynamic cluster quantum Monte Carlo simulations, we study the superconducting behavior of a 1/8 doped two-dimensional Hubbard model with imposed uni-directional stripe-like charge density wave modulation. We find a significant increase of the pairing correlations and critical temperature relative to the homogeneous system when the modulation length-scale is sufficiently large. With a separable form of the irreducible particle-particle vertex, we show that optimized superconductivity is obtained for moderate modulation strength due to a delicate balance between the modulation enhanced pairing interaction, and a concomitant suppression of the bare particle-particle excitations by a modulation reduction of the quasi-particle weight.