Document DOI: 10.1209/epl/i1998-00378-5
Europhys. Lett, 43 (4), pp. 439-444 (1998)
Current responses and voltage fluctuations
in Josephson-junction systems
M.-S. Choi 1, M. Y. Choi 2 and S.-I. Lee 1
1 Department of Physics,
Pohang University of Science and Technology
Pohang 790-784, Korea
2 Department of Physics and Center for Theoretical Physics,
Seoul National University
Seoul 151-742, Korea
(received 30 March 1998; accepted in final form 23 June 1998)
PACS. 74.50
- Proximity effects, weak links,
tunneling phenomena, and
Josephson effects.
PACS. 74.25Nf - Response to electromagnetic fields
(nuclear magnetic resonance, surface
impedance, etc.).
PACS. 74.40
- Fluctuations (noise, chaos,
nonequilibrium superconductivity,
localization, etc.).
Abstract:
We consider arrays of Josephson junctions as well as single junctions in both the classical and quantum-mechanical regimes, and examine the generalized (frequency-dependent) resistance, which describes the dynamic responses of such Josephson-junction systems to external currents. It is shown that the generalized resistance and the power spectrum of voltage fluctuations are related via the fluctuation-dissipation theorem. Implications of the obtained relations are also discussed in various experimental situations.
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