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Josephson Junctions (josephson + junction)

Distribution by Scientific Domains
Physics and Astronomy60%

Selected Abstracts

Macroscopic quantum behavior of superconducting quantum interference devices

FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 4-5 2003
M.G. CastellanoArticle first published online: 24 APR 200
Superconducting quantum interference devices (SQUIDs) are made by a superconducting loop interrupted by one or more Josephson junctions. They are described in terms of a macroscopic variable, the magnetic flux, which shows quantum effects such as tunnelling through a potential barrier. Besides making up the source of a quantum state, SQUIDs also provide the instruments necessary for its probing: as a fact, SQUID based magnetometers have a sensitivity approaching the quantum limit. In this paper I will review the working principle of these devices and illustrate the system of SQUIDs realized in my group to test the quantum behavior at a macroscopic level. [source]

Kinks and rotations in long Josephson junctions

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 15 2001
Wolfgang Hauck
Abstract Kinks and rotations are studied in long Josephson junctions for small and large surface losses. Geometric singular perturbation theory is used to prove existence for small surface losses, while numerical continuation is necessary to handle large surface losses. A survey of the system behaviour in terms of dissipation parameters and bias current is given. Linear orbital stability for kinks is proved for small surface losses by calculating the spectrum of the linearized problem. The spectrum is split into essential spectrum and discrete spectrum. For the determination of the discrete spectrum, robustness of exponential dichotomies is used. Puiseux series together with perturbation theory for linear operators are an essential tool. In a final step, a smooth Evans function together with geometric singular perturbation theory is used to count eigenvalues. For kinks, non-linear orbital stability is shown. For this purpose, the asymptotic behaviour of a semigroup is given and the theory of centre and stable manifolds is applied. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Synchronization of strongly interacting overdamped Josephson junctions

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2005
Alexander Grib
Abstract The high frequency approximation is applied for the description of phase locking in the chain of two junctions loaded by the arbitrary resonance system providing strong coupling. The derived equation of synchronization describes phase locking for junctions which McCumber parameters of an order of magnitude larger than those described in ranges of the slowly varying amplitude approximation. The developed method is applied to the chain of junctions loaded by a resonant transmission line. Obtained values of the voltage locking interval and the maximal tolerant spread of critical currents are in agreement with numerical calculations. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Microwave detection using Josephson junction arrays integrated in a resonator

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2005
Oleksandr M. Ivanyuta
Abstract The possibilities and physical mechanisms of detection of microwave X- and Ka-band radiation by high-temperature superconducting (HTS) YBa2Cu3O7-0.05 (YBCO) bicrystalline Josephson junctions (JJ) embedded in a surface wave resonator (SWR) are considered. Microwave detection was investigated experimentally by using a linear Josephson junction array (JJA) embedded in the SWR. Measurements were carried out starting from the critical temperature of HTS film (T = 92 K), down to the liquid nitrogen level (T = 77 K) and beyond (down to 20 K) using the Gifford-McMahon closed-cycle cryo-cooler. The sensitivity of such type of detectors was determined to be approximately 104 V/W. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]