Determinant Quantum Monte Carlo Study of the Enhancement of d-wave Pairing by Charge Inhomogeneity

TL;DR

This study uses determinant Quantum Monte Carlo to demonstrate that imposing stripe charge patterns in the 2D Hubbard model enhances d-wave pairing, linked to increased antiferromagnetic order and magnetic phase shifts.

Contribution

It shows that charge inhomogeneity in the form of stripe patterns can significantly boost d-wave pairing in the Hubbard model, revealing a potential mechanism for high-temperature superconductivity.

Findings

Stripe patterns enhance d-wave pairing vertex.

Antiferromagnetic order increases with stripe formation.

Observation of a c-phase shift in magnetic order.

Abstract

Striped phases, in which spin, charge, and pairing correlations vary inhomogeneously in the CuO_2 planes, are a known experimental feature of cuprate superconductors, and are also found in a variety of numerical treatments of the two dimensional Hubbard Hamiltonian. In this paper we use determinant Quantum Monte Carlo to show that if a stripe density pattern is imposed on the model, the d-wave pairing vertex is significantly enhanced. We attribute this enhancement to an increase in antiferromagnetic order which is caused by the appearence of more nearly half-filled regions when the doped holes are confined to the stripes. We also observe a \pi-phase shift in the magnetic order.