Journal of the Physical Society of Japan

Coupling Effect in Dual Three-Josephson-Junction Loops in Classical Regime

Yoshihiro Shimazu

Published Jul 15, 2004• 2 citations

Abstract

We investigate the behavior of dual three-Josephson-junction loops coupled through a mutual inductance in the classical regime. The energy levels and the circulating currents in the loops are calculated as a function of applied external magnetic flux. The calculation shows that the coupling effect leads to the sequential reversal of the circulating currents in the loops. We measured the magnetic flux due to the circulating currents with a DC-SQUID in a flux-locked loop configuration. We demonstrate that the states of the coupled system can be manipulated with a magnetic field. The observed magnetic flux agrees very well with the simulation results based on the measurement of an inductance associated with a superconducting wire. The observed reversal of the circulating currents is explained in terms of the noise-activated escape from the metastable state in a six-dimensional potential.

DOI: 10.1143/jpsj.73.1914

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