Ferromagnetic fluctuation and superconductivity in Na 0.35CoO2·1.3H2O: FLEX study of multi-orbital Hubbard model

Masahito Mochizuki, Youichi Yanase, Masao Ogata

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Spin and charge fluctuations and superconductivity in Na0.35CoO2·1. 3H2O are studied based on a multi-orbital Hubbard model. By applying the fluctuation exchange (FLEX) approximation, we show that the Hund's-rule coupling between the Co t2g orbitals causes ferromagnetic spin fluctuation. Triplet pairing is favored by this ferromagnetic fluctuation on the hole-pocket band. We propose that, in Na0.35CoO2·1.3H2O, Co t2g orbitals and inter-orbital Hund's-rule coupling play important roles on the triplet pairing, and this compound can be a first example of the triplet superconductor mediated by inter-orbital interaction-induced ferromagnetic fluctuation.

Original languageEnglish
Pages (from-to)594-596
Number of pages3
JournalPhysica B: Condensed Matter
Issue numberSPEC. ISS.
Publication statusPublished - 2005 Apr 30
Externally publishedYes


  • Hund's-rule coupling
  • NaCoO·1.3HO
  • Orbital degree of freedom
  • Triplet superconductivity

ASJC Scopus subject areas

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


Dive into the research topics of 'Ferromagnetic fluctuation and superconductivity in Na <sub>0.35</sub>CoO<sub>2</sub>·1.3H<sub>2</sub>O: FLEX study of multi-orbital Hubbard model'. Together they form a unique fingerprint.

Cite this