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Volumn 72, Issue 12, 1994, Pages 1870-1873

Anisotropic superconductivity in the 2D Hubbard model: Gap function and interaction weight

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[No Author keywords available]

Indexed keywords


EID: 3342942214     PISSN: 00319007     EISSN: None     Source Type: Journal    
DOI: 10.1103/PhysRevLett.72.1870     Document Type: Article
Times cited : (168)

References (24)
  • 1
    • 84927865064 scopus 로고    scopus 로고
    • Z. X. Shen et al., Phys. Rev. Lett. bf 70, 1553 (1993).
  • 2
    • 84927865063 scopus 로고    scopus 로고
    • D.Wollman et al. (to be published).
  • 6
    • 84927865059 scopus 로고    scopus 로고
    • Phenomenological studies of a dx2-y2 pairing mechanism have been performed by P. Monthoux and D. Pines, Phys. Rev. Lett. bf 69, 961 (1992); and by S. Lenck, J.P. Carbotte, and R.C. Dynes (to be published).
  • 7
    • 84927865058 scopus 로고    scopus 로고
    • The present work uses a slightly different version of the FLEX approximation from that in Refs., Ref. 4, Ref. 5, Specifically, the exchange of s wave singlet pairs is omitted here. For this reason, the transition temperatures reported below are roughly 20 in, Ref. 5
  • 8
    • 84927865057 scopus 로고    scopus 로고
    • Zh. Eksp. Teor. Fiz. bf 34, 1438 (1958) [Sov. Phys. JETP bf 7, 996 (1958)].
    • Migdal, A.B.1
  • 11
    • 84927865055 scopus 로고    scopus 로고
    • A familiar semiquantitative construction of this type is the Coulomb pseudopotential in electron phonon strong coupling theory.
  • 12
    • 0001227357 scopus 로고
    • An alternate approach, useful in approximations which contain convolution integrals, is the fast Fourier transform technique [J.W. Serene and D.W. Hess
    • bf 44
    • An alternate approach, useful in approximations which contain convolution integrals, is the fast Fourier transform technique [J.W. Serene and D.W. Hess, Phys. Rev. B bf 44, 3391 (1991)].
    • (1991) Phys. Rev. B , vol.3391
  • 13
    • 84927865053 scopus 로고    scopus 로고
    • For a detailed description of this division see, Ref. 10
  • 14
    • 84927865052 scopus 로고    scopus 로고
    • Vertex renormalizations have already been carried out in a full parquet approximation for the Anderson impurity model, see, Ref. 9
  • 15
    • 0542424381 scopus 로고
    • The FLEX equations for the superconducting phase were written down in the context of a BCS like treatment by Chien Hua Pao and N.E. Bickers
    • bf 44
    • The FLEX equations for the superconducting phase were written down in the context of a BCS like treatment by Chien Hua Pao and N.E. Bickers, Phys. Rev. B bf 44, 10270 (1991).
    • (1991) Phys. Rev. B , vol.10270
  • 16
    • 84927865051 scopus 로고    scopus 로고
    • Our solution for φ(k) retains dx2-y2 symmetry at all temperatures below Tc. In principle, other solutions may exist which mix different representations at sufficiently low temperature, even though only the dx2-y2 solution is allowed for T→ Tc. We have not performed a search for more general solutions.
  • 17
    • 84927865050 scopus 로고    scopus 로고
    • We have not yet studied the effect of a momentum space RG on calculations in the superconducting state. Such an RG is highly successful in the normal state (Ref. 10) and would allow additional flexibility in treating the superconducting state (e.g., in performing precise integrations near the gap nodes).
  • 18
    • 84927865049 scopus 로고    scopus 로고
    • Using Ω6 rather than Ω0 is analogous to using the phonon Debye frequency, rather than a multiple of the bandwidth, in electron phonon treatments. Note, however, that the effective action used with Ω6 is determined quantitatively by the RG.
  • 20
    • 84927865048 scopus 로고    scopus 로고
    • The detailed frequency dependence of the pairing interaction is strongly affected by the opening of the gap. This dependence is not reflected directly by the integrated weight.
  • 21
    • 84927865047 scopus 로고    scopus 로고
    • For the dx2-y2 state, the full spin susceptibility chis (not calculated here) is expected to vanish linearly at low T for Q = 0, ω = 0. This is not a required property of bar{ chi}s (which contains no vertex corrections).
  • 22
    • 84927865046 scopus 로고    scopus 로고
    • The gap was extracted directly from the imaginary part of the diagonal real frequency Green's function using a Padé approximant continuation. Note that due to the presence of the frequency dependent quantity ξk the gap Δ(ω) is not simply φ (ω)/Z(ω) as in the electron phonon problem.
  • 24
    • 84927865045 scopus 로고    scopus 로고
    • See, e.g., S. W. Cheong et al., Phys. Rev. Lett. bf 67, 1791 (1991).


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.