Phase diagram of half-filled square lattice for frustrated Hubbard model

Seiichiro Onari, Hisatoshi Yokoyama, Yukio Tanaka

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Although the single-band Hubbard model for a half-filled square lattice is considered to be an antiferromagnetic (AF) insulator, it is a current vital question to ask what happens if the second nearest-neighbor hopping (t′) is introduced to it. To study this problem, we use the fluctuation exchange (FLEX) approximation together with the variational Monte Carlo (VMC) method. We have obtained basically consistent results: A first-order Mott transition takes place at the Coulomb repulsion U = Uc for a wide range of t′, and robust d-wave SC whose transition temperature is more than 0.01t (t is the nearest-neighbor hopping) appears near the AF and the Mott insulator region. We have also found that the superconductivity as well as an AF long-range order is suppressed as t′ increases, because the AF spin fluctuation becomes weaker.

Original languageEnglish
Pages (from-to)120-122
Number of pages3
JournalPhysica C: Superconductivity and its Applications
Volume463-465
Issue numberSUPPL.
DOIs
Publication statusPublished - Oct 1 2007
Externally publishedYes

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Spin fluctuations
Hubbard model
Superconductivity
Superconducting transition temperature
Phase diagrams
Monte Carlo methods
phase diagrams
insulators
Monte Carlo method
superconductivity
transition temperature
approximation

Keywords

  • Hubbard model
  • Spin frustration
  • Superconductivity

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Phase diagram of half-filled square lattice for frustrated Hubbard model. / Onari, Seiichiro; Yokoyama, Hisatoshi; Tanaka, Yukio.

In: Physica C: Superconductivity and its Applications, Vol. 463-465, No. SUPPL., 01.10.2007, p. 120-122.

Research output: Contribution to journalArticle

Onari, Seiichiro ; Yokoyama, Hisatoshi ; Tanaka, Yukio. / Phase diagram of half-filled square lattice for frustrated Hubbard model. In: Physica C: Superconductivity and its Applications. 2007 ; Vol. 463-465, No. SUPPL. pp. 120-122.
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