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

Seiichiro Onari, Hisatoshi Yokoyama, Yukio Tanaka

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


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
Issue numberSUPPL.
Publication statusPublished - Oct 1 2007


  • Hubbard model
  • Spin frustration
  • Superconductivity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


Dive into the research topics of 'Phase diagram of half-filled square lattice for frustrated Hubbard model'. Together they form a unique fingerprint.

Cite this