Stability of the superconducting state in the two-band Hubbard model on a triangular lattice

Kenji Kobayashi, Hisatoshi Yokoyama

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

As a model of the novel superconductor NaxCoO2 · yH2O, we study a triangular Hubbard model with doubly degenerate atomic orbitals, using an optimization variational Monte Carlo method. It is found that when the isolated Fermi surface overlaps the van Hove singularity points, dx2 -y2 and d + id-wave superconducting states, among various pairing symmetries, are appreciably stabilized by large Coulomb interactions. The pairing is originating from the potential energy gain induced dominantly by the enhancement of antiferromagnetic spin correlations. The possibility of triplet pairing is very slight in this model.

Original languageEnglish
Pages (from-to)162-165
Number of pages4
JournalPhysica C: Superconductivity and its applications
Volume445-448
Issue number1-2
DOIs
Publication statusPublished - 2006 Oct 1

Keywords

  • Cobalt oxide
  • Hubbard model
  • Pairing symmetry
  • Variational Monte Carlo method

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Stability of the superconducting state in the two-band Hubbard model on a triangular lattice'. Together they form a unique fingerprint.

Cite this