Energy levels quantization in underdamped niobium Josephson junctions

Citation
B. Ruggiero et al., Energy levels quantization in underdamped niobium Josephson junctions, IEEE APPL S, 9(2), 1999, pp. 3978-3981
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
ISSN journal
1051-8223 → ACNP
Volume
9
Issue
2
Year of publication
1999
Part
3
Pages
3978 - 3981
Database
ISI
SICI code
1051-8223(199906)9:2<3978:ELQIUN>2.0.ZU;2-6
Abstract
Macroscopic quantum effects in Josephson systems have recently attracted in terest in the scientific community both for the physics involved and In vie w of applications. Here we present experiments on the presence of energy le vels quantization at temperatures above the classical-quantum regime crosso ver temperature in different Josephson junctions. This has been possible by extending the measurements of the escape rate out of the zero-voltage stat e at higher sweeping bias rate (dI/dt up to 100 A/sec) in order to induce n onstationary conditions in the energy potential describing the junction dyn amics. Our measurements allow us to obtain as fitting parameter the "effect ive" resistance to be used in the RSJ model which is compatible with the su bgap resistance at very low voltage. The very low dissipation level obtaine d at low temperatures renders our results quite interesting in view of appl ications in the quantum limit.