Experimental investigation of the chaotification of a Duffing-like electronic oscillator under two-frequency excitation.

Two-frequency excitation has recently emerged as an efficient method to generate strong chaotification of Duffing and Duffing-like dynamical systems with both single- and double-well potentials. For the systems with a double-well potential, large continuous regions with robust chaos (chaotic attractor insensitive to changes in the system parameters) have been predicted to exist when the method is applied. Motivated by these theoretical results, in this work, we investigate experimentally the chaotification under two-frequency excitation of a simple electronic circuit analogous to the double-well Duffing oscillator. The experimental results confirm the theoretical expectations, and a strong chaotification is observed. Evidences are also presented that the chaotic attractor is robust. Therefore, the work establishes experimentally the two-frequency excitation as a simple and reliable method of chaotification. Furthermore, because of its ease of fabrication, the experimental results turn the particular circuit considered in this work into an interesting practical alternative as a reliable source of continuous-time chaotic signals.