Multistability induced by two symmetric stable node-foci in modified canonical Chua’s circuit

Abstract

This paper proposes a modified canonical Chua’s circuit using an one-stage op-amp-based negative impedance converter and an anti-parallel diode pair. Unlike the conventional Chua’s circuit, this modified canonical Chua’s circuit has one unstable zero node-focus and two stable nonzero node-foci, but complex dynamical behaviors including period, chaos, stable point, and coexisting bifurcation modes are numerically revealed and experimentally verified. Up to six kinds of coexisting multiple attractors, i.e., left-right limit cycles, left-right chaotic spiral attractors and left-right point attractors, are numerically depicted and physically captured. Furthermore, with dimensionless Chua’s equations, dynamical properties of the Chua’s system are investigated, and two symmetric stable nonzero node-foci are validated to exist in the selected parameter regions thus resulting in the emergence of multistability. Specially, multistability with six different steady states is revealed in a narrow parameter range. Within this parameter region, three bifurcation routes are displayed under different initial conditions, and three sets of topologically different and disconnected attractors are observed.