Ferromagnetic fluctuation and possible triplet superconductivity in NaxCoO2•yH2O:: Fluctuation-exchange study of the multiorbital Hubbard model -: art. no. 147005

被引：88

作者：

Mochizuki, M ^{[1
]}

Yanase, Y ^{[1
]}

Ogata, M ^{[1
]}

机构：

[1] Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan

来源：

PHYSICAL REVIEW LETTERS | 2005年 / 94卷 / 14期

关键词：

D O I：

10.1103/PhysRevLett.94.147005

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Spin and charge fluctuations and superconductivity in Na(x)CoO(2)center dot yH(2)O are studied based on a multiorbital Hubbard model. Tight-binding parameters are determined to reproduce the results of band calculations. By applying the fluctuation-exchange approximation, we show that the Hund's-rule coupling between the Co t(2g) orbitals causes ferromagnetic (FM) spin fluctuation. Triplet f(y(y)(2)-3x(2))-wave and p-wave pairings are favored by this FM fluctuation on the hole-pocket band. We propose that, in Na(x)CoO(2)center dot yH(2)O, the Co t(2g) orbitals and interorbital Hund's-rule coupling play important roles on the triplet pairing, and this compound can be a first example of the triplet superconductor in which the orbital degrees of freedom play substantial roles.

引用

页数：4

共 38 条

[1] THE RESONATING VALENCE BOND STATE IN LA2CUO4 AND SUPERCONDUCTIVITY [J].

ANDERSON, PW .

SCIENCE, 1987, 235 (4793) :1196-1198

[2] RESONATING VALENCE BONDS - NEW KIND OF INSULATOR [J].

ANDERSON, PW .

MATERIALS RESEARCH BULLETIN, 1973, 8 (02) :153-160

[3] Electronic model for CoO2 layer based systems:: Chiral resonating valence bond metal and superconductivity -: art. no. 097003 [J].

Baskaran, G .

PHYSICAL REVIEW LETTERS, 2003, 91 (09)

[4]

BAYRAKCI SP, CONDMAT0410224

[5] Ferromagnetic in-plane spin fluctuations in NaxCoO2 observed by neutron inelastic scattering -: art. no. 197201 [J].

Boothroyd, AT ;

Coldea, R ;

Tennant, DA ;

Prabhakaran, D ;

Helme, LM ;

Frost, CD .

PHYSICAL REVIEW LETTERS, 2004, 92 (19) :197201-1

[6] Bulk electronic structure of Na0.35CoO2•1.3H2O -: art. no. 180508 [J].

Chainani, A ;

Yokoya, T ;

Takata, Y ;

Tamasaku, K ;

Taguchi, M ;

Shimojima, T ;

Kamakura, N ;

Horiba, K ;

Tsuda, S ;

Shin, S ;

Miwa, D ;

Nishino, Y ;

Ishikawa, T ;

Yabashi, M ;

Kobayashi, K ;

Namatame, H ;

Taniguchi, M ;

Takada, K ;

Sasaki, T ;

Sakurai, H ;

Takayama-Muromachi, E .

PHYSICAL REVIEW B, 2004, 69 (18) :180508-1

[7] Thermodynamic and transport measurements of superconducting Na0.3CoO2•1.3H2O single crystals prepared by electrochemical deintercalation -: art. no. 157004 [J].

Chou, FC ;

Cho, JH ;

Lee, PA ;

Abel, ET ;

Matan, K ;

Lee, YS .

PHYSICAL REVIEW LETTERS, 2004, 92 (15) :157004-1

[8] Unconventional superconductivity and electron correlations in the cobalt oxyhydrate Na0.35CoO2•yH2O from nuclear quadrupole resonance -: art. no. 047004 [J].

Fujimoto, T ;

Zheng, GQ ;

Kitaoka, Y ;

Meng, RL ;

Cmaidalka, J ;

Chu, CW .

PHYSICAL REVIEW LETTERS, 2004, 92 (04) :4

[9] Possible unconventional superconductivity in NaxCoO2•yH2O probed by muon spin rotation and relaxation -: art. no. 134508 [J].

Higemoto, W ;

Ohishi, K ;

Koda, A ;

Saha, SR ;

Kadono, R ;

Ishida, K ;

Takada, K ;

Sakurai, H ;

Takayama-Muromachi, E ;

Sasaki, T .

PHYSICAL REVIEW B, 2004, 70 (13) :134508-1

[10] Possibility of f-wave spin-triplet superconductivity in the CoO2 superconductor:: A case study on a 2D triangular lattice in the repulsive Hubbard model [J].

Ikeda, H ;

Nisikawa, Y ;

Yamada, K .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2004, 73 (01) :17-20

← 1 2 3 4 →