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=−k B Σ [f lnf+(1−f) ln (1−f)], where we take the quasiparticle spectrum to be the same as in the BCS (weak-coupling) theoryE 2 k =(ε 2 k +Δ2). 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)/k B T c . 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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
J. Bardeen, L. N. Cooper, and J. R. Schrieffer,Phys. Rev. 108, 1175 (1957).
R. Meservey and B. B. Schwartz, inSuperconductivity, Vol. I, R. D. Parks, ed. (Marcel Dekker, New York, 1969), Chap. 3.
D. J. Scalapino,ibid. in, Chap. 10.
W. L. McMillan and J. M. Rowell,ibid. in, Chap. 11.
D. K. Finnemore and D. E. Mapother,Phys. Rev. 140, A507 (1965).
J. C. Swihart,Phys. Rev. 131, 73 (1963);IBM J. Res. and Dev. 6, 14 (1962).
J. R. Clem,Ann. Phys. 40, 268 (1966).
B. Mühlschlegel,Z. Physik 155, 313 (1959).
H. Padamsee, J. E. Neighbor, and C. A. Shiffman,Phys. Letters 41A, 427 (1972).
D. L. Decker, D. E. Mapother, and R. W. Shaw,Phys. Rev. 112, 1888 (1958).
T. Ohtsuka and Y. Kimura,Physica 55, 562 (1972).
H. A. Leopold and H. A. Boorse,Phys. Rev. 134, A1322 (1964).
J. Ferriera da Silva, E. A. Burgemeister, and Z. Dokoupil,Physica 41, 409 (1969).
D. U. Gubser,Phys. Rev. B6, 827 (1972).
H. Padamseeet al., unpublished.
A. M. Toxen,Phys. Rev. Letters 15, 462 (1965).
G. M. Eliashberg,Soviet Phys.—JETP 16, 780 (1963).
G. Grimvall,J. Phys. Chem. Solids 29, 1221 (1968);Solid State Commun. 7, 213 (1969);Phys. Kond. Materie 9, 283 (1969).
P. B. Allen and M. L. Cohen,Phys. Rev. B1, 1329 (1970).
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).
M. H. Lambert,Phys. Rev. B3, 4416 (1971).
R. C. Dynes,Solid State Commun. 10, 615 (1972); W. L. McMillan,Phys. Rev. 167, 331 (1968).
J. G. Adler, J. E. Jackson, and B. S. Chandrasekhar,Phys. Rev. Letters 16, 53 (1966); B. R. Sood,Phys. Rev. 6B, 136 (1972).
H. V. Culbert, D. E. Farrell, and B. S. Chandrasekhar,Phys. Rev. B3, 794 (1971).
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).
L. Y. L. Shen, N. M. Senozan, and N. E. Phillips,Phys. Rev. Letters 14, 1025 (1965).
D. Markowitz and L. P. Kadanoff,Phys. Rev. 131, 563 (1963).
G. J. Culler, B. D. Fried, R. W. Huff, and J. R. Schrieffer,Phys. Rev. Letters 10, 399 (1962).
G. M. Eliashberg,Soviet Phys.—JETP 11, 696 (1960).
R. Balian and C. de Dominicis,Ann. Phys. 62, 229 (1971).
R. E. Prange and L. P. Kadanoff,Phys. Rev. 134, A566 (1964).
W. E. Hubin and D. M. Ginsberg,Phys. Rev. 188, 716 (1969).
J. F. Cochran, C. A. Shiffman, and J. E. Neighbor,Rev. Sci. Instr. 37, 499 (1966).
Y. Nakagawa and A. D. B. Woods,Phys. Rev. Letters 11, 271 (1963).
Author information
Authors and Affiliations
Additional information
Supported in part by the U.S. Atomic Energy Commission under Contract No. AT(30-1)-3972.
Rights and permissions
About this article
Cite this article
Padamsee, H., Neighbor, J.E. & Shiffman, C.A. Quasiparticle phenomenology for thermodynamics of strong-coupling superconductors. J Low Temp Phys 12, 387–411 (1973). https://doi.org/10.1007/BF00654872
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00654872