Abstract
We present experiments on macroscopic quantum effects in Josephson junctions with different relevant junction parameters at a temperature well above the classical-quantum crossover temperature. This has been possible by extending the measurements on the escape rate out of the metastable state at higher sweeping frequency (dI/dt up to 100 A/sec.) in order to induce non-stationary conditions in the energy potential describing the junction dynamics. The non-stationary regime for the system allows a direct observation of energy level quantitation when the rate of change of the external energy, measured in terms of the level spacing, is fast with respect to the thermal transitions between levels.
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REFERENCES
A. D. Caldeira and A. J. Leggett, Phys. Rev. Lett. 46, 211 (1981). See also A. J. Leggett, in Yu. Kagan and A. J. Leggett, eds., Quantum Tunneling in Condensed Media (Elsevier, Amsterdam, 1992), vol. 2, and references therein; and A. Leggett, J. Supercond. 12, 683 (1999).
A. Barone and G. Paternò, in Physics and Applications of Josephson Effect (Wiley, New York, 1982), chap. 6.
A. I. Larkin and Yu. N. Ovchinnikov, Zh. Eksp. Teor. Fiz. 91, 318 (1986) [Sov. Phys. JETP 64, 185 (1986)].
S. Washburn, R. F. Voss, R. A. Webb, and S. Faris, Phys. Rev. Lett. 54, 2712 (1985).
M. H. Devoret, J. M. Martinis, D. Esteve, and J. Clarke, Phys. Rev. Lett. 53, 1260 (1984).
J. M. Martinis, M. H. Devoret, and J. Clarke, Phys. Rev. Lett. 55, 1543 (1985); M. H. Devoret, J. M. Martinis, and J. Clarke, Phys. Rev. Lett. 55, 1908 (1985); J. M. Martinis, M. H. Devoret, and J. Clarke, Phys. Rev. B 35, 4682 (1987); and references therein.
D. B. Schwartz, B. Sen, C. N. Archie, and J. Lukens, Phys. Rev. Lett. 57, 1547 (1985).
R. Rouse, Siyuan Han, and J. E. Lukens, Phys. Rev. Lett. 75, 1614 (1995).
N. Hatakenaka, S. Kurihara, and H. Takayanagi, Phys. Rev. B 42, 3987 (1990); J. M. Schmidt, A. N. Clealand, and J. Clarke, Phys. Rev. B 43, 229 (1991); Yu. N. Ovchinnikov, P. Silvestrini, B. Ruggiero, and A. Barone, J. Supercond. 5, 481 (1992); P. Silvestrini, B. Ruggiero, Yu. N. Ovchinnikov, and A. Barone, Phys. Rev. B 53, 67 (1996); P. Silvestrini, B. Ruggiero, and Yu. N. Ovchinnikov, Phys. Rev. B 54, 1246 (1996).
P. Silvestrini, V. G. Palmieri, B. Ruggiero, and M. Russo, Phys. Rev. Lett. 79, 3046 (1997).
D. Esteve, J. M. Martinis, C. Urbina, E. Turlot, M. H. Devoret, H. Grabert, and S. Linkwitz, Physica Scripta T29, 121 (1989)
P. Silvestrini, O. Liengme, and K. E. Gray, Phys. Rev. B 37, 1525 (1988); P. Silvestrini, R. Cristiano, S. Pagano, O. Liengme, and K. E. Gray, Phys. Rev. Lett. 60, 844 (1988); B. Ruggiero, P. Silvestrini, C. Granata, V. G. Palmieri, A. Esposito, and M. Russo, Phys. Rev. B 57, 134 (1998).
L. S. Kuzmin and D. B. Haviland, Phys. Rev. Lett. 67, 2890 (1991).
Y. Nakamura, C. D. Chen, and J. S. Tsai, Phys. Rev. Lett. 79, 2328 (1997); Y. Nakamura and J. S. Tsai, J. Supercond. 12, 799 (1999).
H. A. Kramers, Physica 7, 284 (1940).
M. Buttiker, E. P. Harris, and R. Landauer, Phys. Rev. B 28, 1268 (1983), and references therein.
P. Silvestrini, Yu. N. Ovchinnikov, and R. Cristiano, Phys. Rev. B 41, 7341 (1990); P. Silvestrini, Phys. Lett. A 152, 306 (1991); P. Silvestrini, B. Ruggiero, and A. Esposito, Fiz. Nik. Temp. 22, 195 (1996) [Low Temp. Phys. 22, 252 (1996)].
T. A. Fulton and L. N. Dunkleberger, Phys. Rev. B 9, 4760 (1974).
M. Brune et al., Phys. Rev. Lett. 77, 4887 (1996).
V. Bouchiat et al., J. Suppercond. 12, 789 (1999).
D. Flees, S. Han, and J. Lukens, J. Supercond. 12, 813 (1999).
C. van der Wal and S. E. Mooji, J. Supercond. 12, 807 (1999).
Y. Nakamura, C. D. Chen, and J. S. Tsai, Nature 398, 786 (1999); D. V. Averin, Nature 398, 748 (1999).
For Instance, MQC project-INFN Roma/Napoli-Italy; P. Silvestrini and L. Srodolsky (unpublished).
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Silvestrini, P., Ruggiero, B., Palmieri, V.G. et al. Direct Evidence of Macroscopic Quantum Effects at High Temperature. Journal of Superconductivity 12, 727–733 (1999). https://doi.org/10.1023/A:1007724807820
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DOI: https://doi.org/10.1023/A:1007724807820