Journal of Low Temperature Physics

, Volume 12, Issue 3–4, pp 387–411

Quasiparticle phenomenology for thermodynamics of strong-coupling superconductors

  • H. Padamsee
  • J. E Neighbor
  • C. A. Shiffman
Article

Abstract

We show that reduced critical fields, entropies, and specific heats of superconductors, regardless of “coupling-strength,” can be fitted essentially within experimental errors by curves appropriate to a system of independent fermion quasiparticles. The analysis proceeds from the formula for the entropy of a system of independent fermionsS=−kB Σ [f lnf+(1−f) ln (1−f)], where we take the quasiparticle spectrum to be the same as in the BCS (weak-coupling) theoryEk2=(εk22). The temperature dependence of the energy gap is also taken to be the same as in the BCS theory, the only adjustable parameter being the gap ratio Δ(0)/kBTc. The necessary values of this ratio are found to be in reasonable agreement with the experimental values deduced from electron tunneling and infrared absorption. Some speculations are offered for the paradoxical success of this simple model, based on analogies with the effects of strong coupling in the normal state.

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References

  1. 1.
    J. Bardeen, L. N. Cooper, and J. R. Schrieffer,Phys. Rev. 108, 1175 (1957).Google Scholar
  2. 2.
    R. Meservey and B. B. Schwartz, inSuperconductivity, Vol. I, R. D. Parks, ed. (Marcel Dekker, New York, 1969), Chap. 3.Google Scholar
  3. 3.
    D. J. Scalapino,ibid. in, Chap. 10.Google Scholar
  4. 4.
    W. L. McMillan and J. M. Rowell,ibid. in, Chap. 11.Google Scholar
  5. 5.
    D. K. Finnemore and D. E. Mapother,Phys. Rev. 140, A507 (1965).Google Scholar
  6. 6.
    J. C. Swihart,Phys. Rev. 131, 73 (1963);IBM J. Res. and Dev. 6, 14 (1962).Google Scholar
  7. 7.
    J. R. Clem,Ann. Phys. 40, 268 (1966).Google Scholar
  8. 8.
    B. Mühlschlegel,Z. Physik 155, 313 (1959).Google Scholar
  9. 9.
    H. Padamsee, J. E. Neighbor, and C. A. Shiffman,Phys. Letters 41A, 427 (1972).Google Scholar
  10. 10.
    D. L. Decker, D. E. Mapother, and R. W. Shaw,Phys. Rev. 112, 1888 (1958).Google Scholar
  11. 11.
    T. Ohtsuka and Y. Kimura,Physica 55, 562 (1972).Google Scholar
  12. 12.
    H. A. Leopold and H. A. Boorse,Phys. Rev. 134, A1322 (1964).Google Scholar
  13. 13.
    J. Ferriera da Silva, E. A. Burgemeister, and Z. Dokoupil,Physica 41, 409 (1969).Google Scholar
  14. 14.
    D. U. Gubser,Phys. Rev. B6, 827 (1972).Google Scholar
  15. 15.
    H. Padamseeet al., unpublished.Google Scholar
  16. 16.
    A. M. Toxen,Phys. Rev. Letters 15, 462 (1965).Google Scholar
  17. 17.
    G. M. Eliashberg,Soviet Phys.—JETP 16, 780 (1963).Google Scholar
  18. 18.
    G. Grimvall,J. Phys. Chem. Solids 29, 1221 (1968);Solid State Commun. 7, 213 (1969);Phys. Kond. Materie 9, 283 (1969).Google Scholar
  19. 19.
    P. B. Allen and M. L. Cohen,Phys. Rev. B1, 1329 (1970).Google Scholar
  20. 20.
    R. G. Poulsen and W. R. Datars, inProc. LT 12, E. Kanda, ed. (Academic Press of Japan, Tokyo, 1971), p. 617; P. Goy and G. Weisbuch,ibid., p. 615; P. Goy,Phys. Letters 31A, 584 (1970).Google Scholar
  21. 21.
    M. H. Lambert,Phys. Rev. B3, 4416 (1971).Google Scholar
  22. 22.
    R. C. Dynes,Solid State Commun. 10, 615 (1972); W. L. McMillan,Phys. Rev. 167, 331 (1968).Google Scholar
  23. 23.
    J. G. Adler, J. E. Jackson, and B. S. Chandrasekhar,Phys. Rev. Letters 16, 53 (1966); B. R. Sood,Phys. Rev. 6B, 136 (1972).Google Scholar
  24. 24.
    H. V. Culbert, D. E. Farrell, and B. S. Chandrasekhar,Phys. Rev. B3, 794 (1971).Google Scholar
  25. 25.
    G. Brändli and P. N. Trofimenkoff,Phys. Letters 36A, 431 (1971); J. G. Adler, J. E. Jackson, and T. A. Will,Phys. Letters 24A, 407 (1967).Google Scholar
  26. 26.
    L. Y. L. Shen, N. M. Senozan, and N. E. Phillips,Phys. Rev. Letters 14, 1025 (1965).Google Scholar
  27. 27.
    D. Markowitz and L. P. Kadanoff,Phys. Rev. 131, 563 (1963).Google Scholar
  28. 28.
    G. J. Culler, B. D. Fried, R. W. Huff, and J. R. Schrieffer,Phys. Rev. Letters 10, 399 (1962).Google Scholar
  29. 29.
    G. M. Eliashberg,Soviet Phys.—JETP 11, 696 (1960).Google Scholar
  30. 30.
    R. Balian and C. de Dominicis,Ann. Phys. 62, 229 (1971).Google Scholar
  31. 31.
    R. E. Prange and L. P. Kadanoff,Phys. Rev. 134, A566 (1964).Google Scholar
  32. 32.
    W. E. Hubin and D. M. Ginsberg,Phys. Rev. 188, 716 (1969).Google Scholar
  33. 33.
    J. F. Cochran, C. A. Shiffman, and J. E. Neighbor,Rev. Sci. Instr. 37, 499 (1966).Google Scholar
  34. 34.
    Y. Nakagawa and A. D. B. Woods,Phys. Rev. Letters 11, 271 (1963).Google Scholar

Copyright information

© Plenum Publishing Corporation 1973

Authors and Affiliations

  • H. Padamsee
    • 1
  • J. E Neighbor
    • 1
  • C. A. Shiffman
    • 1
  1. 1.Department of PhysicsNortheastern UniversityBoston

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