Document Type

Article

Publication Date

August 2008

Publication Title

Physical Review B

Volume

78

Issue Number

6

DOI

10.1103/PhysRevB.78.060502

Keywords

Hopping, Hubbard, Holstein, Parameters, Antiferromagnetic, Polaronic, Enhances

Disciplines

Astrophysics and Astronomy | Physical Sciences and Mathematics | Physics

Abstract

We study the effect of long-range hoppings on Tc for the two-dimensional (2D) Hubbard model with and without Holstein phonons using parameters evaluated from band-structure calculations for cuprates. Employing the dynamical cluster approximation (DCA) with a quantum Monte Carlo (QMC) cluster solver for a 4-site cluster, we observe that without phonons, the long-range hoppings, t′ and t′′, generally suppress Tc. We argue that this trend remains valid for larger clusters. In the presence of the Holstein phonons, a finite t′ enhances Tc in the under-doped region for the hole-doped system, consistent with local-density approximation (LDA) calculations and experiment. This is interpreted through the suppression of antiferromagnetic (AF) correlations and the interplay between polaronic effects and the antiferromagnetism.

Comments

This article originally appeared in Physical Review B, volume 78, issue 6, 2008, published by the American Physical Society. ©2008 American Physical Society. The article can also be found online at this link.
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