Mutual locking, chaos and devils staircase in two Josephson tunnel junctions with a common resistive shunt

Author

Jensen, H.D. ; Larsen, A. ; Mygind, J. ; Levinsen, M.T.

Author_Institution

Danish Inst. of Fundamental Metrol., Lyngby, Denmark

Volume

25

Issue

2

fYear

1989

fDate

3/1/1989 12:00:00 AM

Firstpage

1412

Lastpage

1415

Abstract

The authors studied the phase-locking in a pair of individually biased, resistively and capacitively shunted Josephson junctions, coupled by a common resistive or capacitive shunt, on an analog computer. Under certain conditions, locking is found to occur at all rational frequency ratios. A critical line is found in parameter space along which the steps form a complete devil´s staircase having a fractal dimension of 0.87. Beyond the critical line bifurcations occur on all steps following the Feigenbaum sequence to chaos. The Feigenbaum constants are recovered to a fair accuracy. Preliminary experiments with two Josephson tunnel junctions shunted on the chip by a gold-indium film are discussed

Keywords

Josephson effect; chaos; equivalent circuits; stability; superconducting junction devices; Au-In film shunt; AuIn; Feigenbaum sequence; Josephson tunnel junctions; Pb alloy electrodes; bifurcations; capacitive shunt; chaos; circuit models; common resistive shunt; critical line; devils staircase; fractal dimension; individually-biased junction pair; mutual locking; parameter space; phase-locking; superconducting junctions; Analog computers; Bifurcation; Capacitance; Chaos; Coupling circuits; Critical current; Fractals; Frequency; Josephson junctions; Voltage;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.92560

Filename

92560