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Article
Finite-temperature superconducting correlations of the Hubbard model
Physical Review B (2015)
  • Ehsan Khatami, San Jose State University
  • Richard T. Scalettar, University of California, Davis
  • Rajiv R.P. Singh, University of California, Davis
Abstract
We utilize numerical linked-cluster expansions (NLCEs) and the determinantal quantum Monte Carlo algorithm to study pairing correlations in the square-lattice Hubbard model. To benchmark the NLCE, we first locate the finite-temperature phase transition of the attractive model to a superconducting state away from half filling. We then explore the superconducting properties of the repulsive model for the d-wave and extended s-wave pairing symmetries. The pairing structure factor shows a strong tendency to d-wave pairing and peaks at an interaction strength comparable to the bandwidth. The extended s-wave structure factor and correlation length are larger at higher temperatures but clearly saturate as temperature is lowered, whereas the d-wave counterparts, which start off lower at high temperatures, continue to rise near half filling. This rise is even more dramatic in the d-wave susceptibility. The convergence of NLCEs breaks down as the susceptibilities and correlation lengths become large, so we are unable to determine the onset of long-range order. However, our results extend the conclusion, previously restricted to only magnetic and charge correlations, that NLCEs offer a unique window into pairing in the Hubbard model at strong coupling.
Publication Date
2015
DOI
10.1103/PhysRevB.91.241107
Publisher Statement
This article originally appeared in Physical Review B, volume 91, issue 24, 2015, published by the American Physical Society. ©2015 American Physical Society. The article can also be found online at this link.

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Citation Information
Ehsan Khatami, Richard T. Scalettar and Rajiv R.P. Singh. "Finite-temperature superconducting correlations of the Hubbard model" Physical Review B Vol. 91 Iss. 24 (2015) ISSN: 2469-9950
Available at: http://works.bepress.com/ehsan_khatami/22/