J. Phys. Soc. Jpn. 71 (2002) pp. 1993-2004 |Next Article| |Table of Contents|
|Full Text PDF (461K)| |Buy This Article|
Roles of Electron Correlations in the Spin-Triplet Superconductivity of Sr2RuO4
Takuji Nomura and
Kosaku Yamada
Department of Physics, Kyoto University, Kyoto 606-8502
(Received March 12, 2002)
We discuss a microscopic mechanism of the spin-triplet superconductivity in the quasi-two-dimensional ruthenium oxide Sr2RuO4 on the basis of two-dimensional three-band Hubbard model. We solve the linearized Éliashberg equation by taking into account the full momentum-frequency dependence of the order parameter for the spin-triplet and the spin-singlet states, and estimate the transition temperature as a function of the Coulomb integrals. The effective pairing interaction is expanded perturbatively with respect to the Coulomb interaction at the Ru sites up to the third order. As a result, we show that the spin-triplet p-wave state is more stable than the spin-singlet d-wave state for moderately strong Coulomb interaction. Our results suggest that one of the three bands, γ, plays a dominant role in the superconducting transition, and the pairing on the other two bands (α and β) is induced passively through the inter-orbit couplings. The most significant momentum dependence for the p-wave pairing originates from the vertex correction terms, while the incommensurate antiferromagnetic spin fluctuations, which are observed in inelastic neutron scattering experiments, are expected to disturb the p-wave pairing by enhancing the d-wave pairing. Therefore we can regard the spin-triplet superconductivity in Sr2RuO4 as one of the natural results of the electron correlations, and cannot consider as a result of some strong magnetic fluctuations. We will also mention the normal Fermi liquid properties of Sr2RuO4.
©2002 The Physical Society of Japan
KEYWORDS:
electron correlations, three-band Hubbard model, third order perturbation theory, vertex corrections, Sr2RuO4, spin-triplet superconductivity, superconducting transition temperature
URL:
http://jpsj.ipap.jp/link?JPSJ/71/1993/
DOI: 10.1143/JPSJ.71.1993
See Also:
- Y. Maeno, H. Hashimoto, K. Yoshida, S. Nishizaki, T. Fujita, J. G. Bednorz and F. Lichtenberg:
Nature 372 (1994) 532[CrossRef].
- Y. Maeno, T. M. Rice and M. Sigrist: Phys. Today 54 (2001) 42.
- K. Ishida, H. Mukuda, Y. Kitaoka, K. Asayama, Z. Q. Mao, Y. Mori and Y. Maeno:
Nature 396 (1998) 658[CrossRef].
- J. A. Duffy, S. M. Hayden, Y. Maeno, Z. Q. Mao, J. Kulda and G. J. McIntyre:
Phys. Rev. Lett. 85 (2000) 5412[APS].
- A. P. Mackenzie, R. K. W. Haselwimmer, A. W. Tyler, G. G. Lonzarich, Y. Mori, S. Nishizaki and Y. Maeno:
Phys. Rev. Lett. 80 (1998) 161[APS].
- K. Ishida, H. Mukuda, Y. Kitaoka, Z. Q. Mao, Y. Mori and Y. Maeno:
Phys. Rev. Lett. 84 (2000) 5387[APS].
- G. M. Luke, Y. Fudamoto, K. M. Kojima, M. I. Larkin, J. Merrin, B. Nachumi, Y. J. Uemura, Y. Maeno, Z. Q. Mao, Y. Mori, H. Nakamura and M. Sigrist:
Nature 394 (1998) 558[CrossRef].
- Z. Q. Mao, Y. Maeno, S. NishiZaki, T. Akima and T. Ishiguro:
Phys. Rev. Lett. 84 (2000) 991[APS].
- S. NishiZaki, Y. Maeno and Z. Q. Mao:
J. Phys. Soc. Jpn. 69 (2000) 572[IPAP].
- Y. Maeno, K. Yoshida, H. Hashimoto, S. Nishizaki, S. Ikeda, M. Nohara, T. Fujita, A. P. Mackenzie, N. E. Hussey, J. G. Bednorz and F. Lichtenberg:
J. Phys. Soc. Jpn. 66 (1997) 1405[IPAP].
- A. P. Mackenzie, S. R. Julian, A. J. Diver, G. J. McMullan, M. P. Ray, G. G. Lonzarich, Y. Maeno, S. Nishizaki and T. Fujita:
Phys. Rev. Lett. 76 (1996) 3786[APS].
- T. Oguchi:
Phys. Rev. B 51 (1995) 1385[APS].
- D. J. Singh:
Phys. Rev. B 52 (1995) 1358[APS].
- T. M. Rice and M. Sigrist:
J. Phys.: Condens. Matter 7 (1995) L643[IoP STACKS].
- I. I. Mazin and D. J. Singh:
Phys. Rev. Lett. 79 (1997) 733[APS].
- P. Monthoux and G. G. Lonzarich:
Phys. Rev. B 59 (1999) 14598[APS].
- Y. Sidis, M. Braden, P. Bourges, B. Hennion, S. Nishizaki, Y. Maeno and Y. Mori:
Phys. Rev. Lett. 83 (1999) 3320[APS].
- T. Kuwabara and M. Ogata:
Phys. Rev. Lett. 85 (2000) 4586[APS].
- K. Kuroki, M. Ogata, R. Arita and H. Aoki:
Phys. Rev. B 63 (2001) 060506[APS].
- F. Servant, B. Fak, S. Raymond, J. P. Brison, P. Lejay and J. Flouquet:
Phys. Rev. B 65 (2002) 184511[APS].
- M. Minakata and Y. Maeno:
Phys. Rev. B 63 (2001) 180504[APS](R).
- M. Braden, O. Friedt, Y. Sidis, P. Boyrges, M. Minakata and Y. Maeno:
Phys. Rev. Lett. 88 (2002) 197002[APS].
- N. Kikugawa and Y. Maeno: preprint.
- T. Takimoto:
Phys. Rev. B 62 (2000) R14641[APS].
- G. Baskaran:
Physica B: 223&224 (1996) 490[Elsevier].
- K. K. Ng and M. Sigrist:
Europhys. Lett. 49 (2000) 473[CrossRef].
- J. Spałek:
Phys. Rev. B 63 (2001) 104513[APS].
- T. Nomura and K. Yamada:
J. Phys. Soc. Jpn. 69 (2000) 3678[IPAP].
- T. Nomura and K. Yamada: to be published in J. Phys. Chem. Solids.
- For example, E. Dagotto, T. Hotta and A. Moreo:
Phys. Rep. 344 (2001) 1[CrossRef].
- T. Nomura and K. Yamada:
J. Phys. Soc. Jpn. 69 (2000) 1856[IPAP].
- A. Damascelli, K. M. Shen, D. H. Lu, N. P. Armitage, F. Ronning, D. L. Feng, C. Kim, Z.-X. Shen, T. Kimura, Y. Tokura, Z. Q. Mao and Y. Maeno: J. Electron Spectrosc. Relat. Phenom. 114 (2001) 641.
- D. F. Agterberg, T. M. Rice and M. Sigrist:
Phys. Rev. Lett. 78 (1997) 3374[APS].
- I. I. Mazin and D. J. Singh:
Phys. Rev. Lett. 82 (1999) 4324[APS].
- M. Sigrist, D. Agterberg, A. Furusaki, C. Honerkamp, K. K. Ng, T. M. Rice and M. E. Zhitomirsky: Phisica C 317–318 (1999) 134.
- I. Bonalde, B. D. Yanoff, M. B. Salamon, D. J. Van Harlingen and E. M. E. Chia:
Phys. Rev. Lett. 85 (2000) 4775[APS].
- C. Lupien, W. A. MacFarlane, C. Proust, L. Taillefer, Z. Q. Mao and Y. Maeno:
Phys. Rev. Lett. 86 (2001) 5986[APS].
- T. Nomura and K. Yamada:
J. Phys. Soc. Jpn. 71 (2002) 404[IPAP].
- N. Okuda, T. Suzuki, Z. Q. Mao, Y. Maeno and T. Fujita:
J. Phys. Soc. Jpn. 71 (2002) 1134[IPAP];
Physica B 312–313 (2002) 800[CrossRef].