On a study of optically coupled memristive Chua circuits—rhythmogenesis and amplitude death

• Two memristive Chua circuits are optically and conjugately coupled.
• The inductance in Chua circuit is replaced with resistance, capacitance, op-amp combination.
• Bi-parametric Lyapunov diagrams are used to locate instability regions.
• Amplitude death and a new event of oscillation generation from steady state are discussed.
• Transient effects are seen to persist in route to both of these phenomena.

Properties of memristive inductorless Chua circuits are studied when they are coupled optically to characterize the oscillation quenching phenomenon of amplitude death (AD) and oscillation generation procedure of rhythmogenesis. The behaviors of these systems, when studied under coupled condition, show some new features which are not seen previously. This phenomenon is really a novel one as it is the generation of oscillation due to the interaction of two such systems each at their respective steady states. The other event is amplitude death (AD) observed by increase in the coupling strength. The numerical simulation is supported with the data obtained via analogue circuit implementation of the system. Two circuits coupled through a LED (light emitting diode) and LDR (photo resistor) pair show transition to chaotic state under parameter variation. The experimental data was collected with the help of digital to analog converter system. Our data indicates that there exist two different routes to chaos—either through period doubling or without it.