We have studied the I-V characteristics, the dc resistance at the origin R(T), and the critical current I c (T) of arrays consisting of n × n (n = 10, 20, 30, and 40) In squares separated by Au/In regions. The superconducting squares have side d s (In) from 7.5 to 15 Μm and d N (Au/In) from 2.5 to 11 Μm. These devices show two transition temperatures in their R(T) curve; one at T cG near T c (In) and another one at T c * above T c (Au/In). The I-V curves for each temperature region resemble recent published results on NbN granular films. These arrays follow a formalism proposed by Wolf, Gubser, and Imry to describe the transition to a resistanceless state at T c *. The measured values of I c (T) are larger than expected from n noninteracting Bardeen-Johnson junctions in parallel, although the exponential behavior in temperature is followed. They are compatible with the idea of bands in the quasiparticle spectrum in the Au/In regions. Deviations in I c (T) from an exponential behavior in T near T c * have been analyzed by applying to SNS arrays ideas developed for phase transitions in SIS arrays. Evidence that at T c * we may be observing a phase transition at T cJ due to the Josephson coupling between In squares exists but it needs the development of theoretical work to be put on more solid grounds.
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References
J. Rosenblatt, Revue Phys. Appl. 9, 217 (1974).
J. L. Berchier and D. H. Sanchez, Revue Phys. Appl. 14, 757 (1979).
D. W. Palmer and J. E. Mercereau, IEEE Trans. Magn. MAG11, 667 (1975).
J. P. Romagnan, A. Gilabert, J. P. Laheurte, J. C. Noiray, and E. Guyon, Solid State Comm. 16, 359 (1975).
J. M. Dupart and J. Baixeras, Appl. Phys. Lett. 30, 123 (1977).
C. R. Spencer, P. Martinoli, E. D. Gibson, J. D. Verhoeven, and D. K. Finnemore, Phys. Rev. B 18, 1216 (1978).
J. L. Berchier and D. H. Sanchez, Rev. Sci. Instrum. 49, 1452 (1978).
J. L. Berchier, Ph.D. Thesis, DPMC, University of Geneva (September 1979), unpublished (in French).
J. L. Berchier and D. H. Sanchez, to be published.
H. A. Notarys and J. E. Mercereau, J. Appl. Phys. 44, 1823 (1973); see also U.S. Patent 3.798.511, March 19, 1974.
D. U. Gubser and S. A. Wolf, J. Phys. (Paris) 39, C6–579 (1978).
S. A. Wolf, D. U. Gubser, and Y. Imry, Phys. Rev. Lett. 42, 324 (1979).
D. U. Gubser and S. A. Wolf, Solid State Commun. 32, 449 (1979).
D. U. Gubser, S. A. Wolf, T. L. Francavilia, and J. L. Feldman, in Inhomogeneous Superconductors Conference (AIP Conf. Proceedings, No. 58, dy1980), p. 159.
S. A. Wolf and W. H. Lowrey, Phys. Rev. Lett. 39, 1038 (1977).
J. Bardeen and J. L. Johnson, Phys. Rev. B 5, 72 (1972).
I. O. Kulik, Zh. Eksp. Teor. Fiz. 57, 1745 (1969). [Sov. Phys. JETP 30, 944 (1970)].
L. M. Geppert, L. G. Hayler, J. T. Chen, and Y. W. Kim, Phys. Rev. B 14, 1062 (1976).
H. A. Notarys, M. L. Yu, and J. E. Mercereau, Phys. Rev. Lett. 30, 743 (1973).
J. M. Dupart, J. Rosenblatt, and J. Baixeras, Phys. Rev. B 16, 4815 (1977).
A. P. Van Gelder, Phys. Rev. 181, 787 (1969).
J. Rosenblatt, H. Cortès, and P. Pelĺan, Phys. Lett 33A, 143 (1970).
T. D. Clark, Phys. Rev. B 8, 137 (1973); P. Pellan, G. Dousselin, H. Cortès, and J. Rosenblatt, Solid State Commun. 11, 427 (1972).
P. Pellan, G. Dousselin, and J. Rosenblatt, Revue Phys. Appl. 8, 471 (1973).
S. E. Barnes, Phys. Lett. 66A, 422 (1978).
J. Rosenblatt, A. Raboutou, and P. Pellan, in Proc. of the LT14 (Otaniemi, Finland), M. Krusius and M. Vuorio, eds. (North-Holland), Vol. 2, pp. 361–364.
P. R. Wallace and M. J. Stavn, Can. J. Phys. 43, 411 (1965).
P. W. Anderson, Phys. Rev. 112, 1900 (1958).
The problems found by the theory are reviewed by J. Imry, in Inhomogeneous Super-conductors Conference (AIP Conf. Proceedings, No. 58, 1980), p. 141.
B. Abeles, Phys. Rev. B 15, 2828 (1977).
W. L. McLean and M. J. Stephen, Phys. Rev. B 19, 5925 (1979).
A. F. Hebard, in Inhomogeneous Superconductors Conference (AIP Conf. Proceedings, No. 58, 1980), p. 129; A. F. Hebard and J. M. Vanderberg, Phys. Rev. Lett. 44, 50 (1980).
J. Rosenblatt, personal communication; see also B. Giovannini and L. Weiss, Solid State Commun. 28, 1005 (1978).
M. Strongin, O. F. Kammerer, J. Crow, R. S. Thompson, and H. L. Fine, Phys. Rev. Lett. 20, 922 (1968); L. G. Aslamazov and A. I. Larkin, Phys. Lett. 26A, 238 (1968).
J. Zittartz, Z. Physik B 23, 55, 63 (1976).
J. M. Kosterlitz and D. J. Thouless, J. Phys. C: Solid State Phys. 6, 1181 (1973); J. M. Kosterlitz, J. Phys. C: Solid State Phys. 7, 1046 (1974).
M. R. Beasley, J. E. Mooij, and T. P. Orlando, Phys. Rev. Lett. 42, 1165 (1979).
S. Doniach and B. A. Huberman, Phys. Rev. Lett. 42, 1169 (1979).
B. I. Halperin and D. R. Nelson, J. Low Temp. Phys. 36, 599 (1979).
A. F. Hebard and A. T. Fiory, in Inhomogeneous Superconductors Conference (AIP Conf. Proceedings, No. 58, 1980), p. 293; Phys. Rev. Lett. 44, 291 (1980).
M. Suzuki, S. Miyashita, and A. Kuroda, Progr. Theor. Phys. 58, 1377 (1977); S. Miyashita, H. Nishimori, A. Kuroda, and M. Suziki, Progr. Theor. Phys. 60, 1669 (1978).
D. H. Sanchez and J. L. Berchier, in Inhomogeneous Superconductors Conference, Berkeley (AIP Conf. Proceedings, No. 58, 1980), p. 239.
B. Giovannini, D. H. Sanchez, and J. L. Berchier, in Inhomogeneous Superconductors Conference (AIP Conf. Proceedings, No. 58, 1980), p. 152.
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Supported by the Swiss National Science Foundation.
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H. Sanchez, D., Berchier, JL. Properties of n × n square arrays of proximity effect bridges. J Low Temp Phys 43, 65–89 (1981). https://doi.org/10.1007/BF00118622
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DOI: https://doi.org/10.1007/BF00118622