Birth of strange nonchaotic attractors through type III intermittency

A new route and the associated mechanism are described for the creation of a strange nonchaotic attractor during the transition from two-frequency quasiperiodicity to a chaotic attractor through torus doubling bifurcation in quasiperiodically forced systems. The strange nonchaotic attractor arises when a a torus doubled attractor is interrupted by a subharmonic bifurcation, resulting in the inhibition of torus doubling sequence. This transition is shown to exhibit type III intermittent characteristic scaling behaviour. The scenario and mechanism are illustrated in detail through experimental and numerical studies of a quasiperiodically driven simple piecewise linear electronic circuit. (C) 1999 Elsevier Science B.V. All rights reserved.