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

Masahito Mochizuki; Youichi Yanase; Masao Ogata

doi:10.1016/j.physb.2005.01.161

Ferromagnetic fluctuation and superconductivity in Na _0.35CoO₂·1.3H₂O: FLEX study of multi-orbital Hubbard model

Masahito Mochizuki^*, Youichi Yanase, Masao Ogata

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

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 language	English
Pages (from-to)	594-596
Number of pages	3
Journal	Physica B: Condensed Matter
Volume	359-361
Issue number	SPEC. ISS.
DOIs	https://doi.org/10.1016/j.physb.2005.01.161
Publication status	Published - 2005 Apr 30
Externally published	Yes

Keywords

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

Access to Document

10.1016/j.physb.2005.01.161

Cite this

@article{2fc8a799d95b416c81d5d7b75821d066,

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

abstract = "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.",

keywords = "Hund's-rule coupling, NaCoO·1.3HO, Orbital degree of freedom, Triplet superconductivity",

author = "Masahito Mochizuki and Youichi Yanase and Masao Ogata",

note = "Funding Information: We thank K. Ishida, G.-q. Zheng, K. Yoshimura, K. Kobayashi, M. Sato, R. Kadono, K. Kuroki, G. Baskaran for valuable discussions. M.M. also thanks S. Onari and Yasuhiro Tanaka for discussions. This work is supported by the Grant-in-Aid for Scientific Research from the MEXT of Japan. ",

year = "2005",

month = apr,

day = "30",

doi = "10.1016/j.physb.2005.01.161",

language = "English",

volume = "359-361",

pages = "594--596",

journal = "Physica B: Condensed Matter",

issn = "0921-4526",

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TY - JOUR

T1 - Ferromagnetic fluctuation and superconductivity in Na 0.35CoO2·1.3H2O

T2 - FLEX study of multi-orbital Hubbard model

AU - Mochizuki, Masahito

AU - Yanase, Youichi

AU - Ogata, Masao

N1 - Funding Information: We thank K. Ishida, G.-q. Zheng, K. Yoshimura, K. Kobayashi, M. Sato, R. Kadono, K. Kuroki, G. Baskaran for valuable discussions. M.M. also thanks S. Onari and Yasuhiro Tanaka for discussions. This work is supported by the Grant-in-Aid for Scientific Research from the MEXT of Japan.

PY - 2005/4/30

Y1 - 2005/4/30

N2 - 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.

AB - 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.

KW - Hund's-rule coupling

KW - NaCoO·1.3HO

KW - Orbital degree of freedom

KW - Triplet superconductivity

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