Abstract
The possibility of generating an occupation inversion n(E) >1/2 in a nonequilibrium superconducting state by tunnel injection is discussed. By investigating the combined densities of states of the processes involved, a condition on the occupation function n(E) for sound wave amplification is derived, which generally is more restrictive than occupation inversion. It is shown that occupation inversion can be generated only in nonsymmetric superconductorinsulator-superconductor tunnel junctions where the super-conducting layers are of different thicknesses. The thickness of the amplifying layer must not exceed the diffusion length of the quasiparticles. The estimates suggest that sound wave amplification should in principle be possible.
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References
L. R. Testardi, Phys. Rev. B 4, 2189 (1971).
W. H. Parker and W. D. Williams, Phys. Rev. Lett. 29, 924 (1972).
G. A. Sai-Halasz, C. C. Chi, A. Denenstein, and D. N. Langenberg, Phys. Rev. Lett. 33, 215 (1974).
M. Goetze, M. Nover, and O. Weis, Z. Phys. B 25, 1 (1976).
L. Giaver, Phys. Rev. Lett. 5, 147 (1960).
I. L. Singer and W. E. Bron, Phys. Rev. B 14, 2832 (1976).
T. M. Klapwijk and J. E. Movij, Physica 81B, 132 (1976).
K. E. Gray, Solid State Comm. 26, 633 (1978).
K. E. Gray, Appl. Phys. Lett. 32, 392 (1978).
Jhy-Jiun Chang and D. J. Scalapino, J. Low Temp. Phys. 31, 1 (1978).
J. Bardeen, G. Rickzyzen, and L. Tewordt, Phys. Rev. 113, 982 (1959).
V. Ambegaokar and L. Tewordt, Phys. Rev. 134A, 805 (1964).
V. P. Seminozhenko, Fiz. Niz. Temp. 4, 867 (1978).
V. E. Novikov, V. P. Seminozhenko, and V. L. Shestopalov, Fiz. Niz. Temp. 5, 837 (1979).
I. K. Kirichenko and V. P. Seminozhenko, Fiz. Niz. Temp. 3, 987 (1977).
J. Schrieffer, Theory of Superconductivity (Benjamin, New York, 1964), §3.2.
H. Dayem and W. F. Eisenmenger, U.S. Patent No. 3405374 (October 8, 1968).
C. S. Owen and D. J. Scalapino, Phys. Rev. Lett. 28, 1559 (1972).
D. L. Miller, Myron Strongin, and O. F. Kammerer, Phys. Rev. B 13, 4834 (1976).
I. O. Kulik and I. K. Janson, in Josephson Effect in Superconducting Tunnelling Structures (in Russian) (Nauka, Moscow 1970), p. 155.
F. Dettmann, FSU Jena, private communication.
G. M. Eliashberg, Zh. Eksp. Teor. Fiz. 61, 1254 (1971).
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Otschik, P., Eschrig, H. & Lange, F. Sound wave amplification in superconductors. J Low Temp Phys 43, 397–408 (1981). https://doi.org/10.1007/BF00116164
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DOI: https://doi.org/10.1007/BF00116164