Mott transitions and d-wave superconductivity in half-filled-band Hubbard model on square lattice with geometric frustration

Hisatoshi Yokoyama, Masao Ogata, Yukio Tanaka

Research output: Contribution to journalArticlepeer-review

99 Citations (Scopus)

Abstract

Mechanisms of Mott transitions and dx2-y2-wave superconductivity (SC) are studied in the half-filledband Hubbard model on square lattices with a diagonal hopping term (t′), using an optimization (or correlated) variational Monte Carlo method. In the trial wave functions, a doublon-holon binding effect is introduced in addition to the onsite Gutzwiller projection. We mainly treat a d-wave singlet state and a projected Fermi sea. In both wave functions, first-order Mott transitions without direct relevance to magnetic orders occur at U = Uc, which is approximately the bandwidth, for arbitrary t′/t. These transitions originate in the binding or unbinding of a doublon to a holon. d-wave SC appears in a narrow range immediately below Uc. The robust d-wave superconducting correlation is necessarily accompanied by enhanced antiferromagnetic correlation; the strength of SC decreases, as t′/t increases.

Original languageEnglish
Article number114706
Journaljournal of the physical society of japan
Volume75
Issue number11
DOIs
Publication statusPublished - 2006 Nov

Keywords

  • Antiferromagnetic correlation
  • Condensation energy
  • Frustration
  • High-T cuprate
  • Hubbard model
  • Mott transition
  • Spin gap
  • Superconductivity
  • Variational Monte Carlo method

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Mott transitions and d-wave superconductivity in half-filled-band Hubbard model on square lattice with geometric frustration'. Together they form a unique fingerprint.

Cite this