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

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 appearance of more nearly half-filled regions when the doped holes are confined to the stripes. We also observe an enhanced $d$-wave pair correlation inside stripes reaching its maximum value when the $\pi$-phase shift in the magnetic order takes place. \\ Reference: Rubem Mondaini and Tao Ying and Thereza Paiva and Richard T. Scalettar, Phys. Rev. B 86, 184506 (2012).