Coherent states in a multi-junction superconducting loop
Institut für Schicht-und Ionentechnik, Forschungszentrum GmbH
D-52425 Jülich, Germany
2 Institut für Festkörperphysik, Friedrich Schiller Universität D-07743 Jena, Germany
Accepted: 16 November 1995
The mutual coherent interaction of Josephson junctions in a multi-junction superconducting loop (MSL) in the limit of zero-loop inductance is theoretically investigated. For the loop containing 2M junctions there are M coherent states corresponding to different values of effective flux in the loop. The stability analysis using the method of Floquet exponents shows the highest stability for the state with . In this state, the MSL behaves like an oscillating magnetic dipole. The optimum stability is reached for the normalised bias current and the McCumber parameter .
PACS: 74.50.+r – Proximity effects, weak links, tunneling phenomena, and Josephson effects / 85.25.Dq – Superconducting quantum interference devices (SQUIDs) (including magnetometers, electromagnetic radiation sources and detectors, and computer logic and memory devices) / 84.30.Ng – Oscillators, pulse generators, and function generators
© EDP Sciences, 1996