Observation of the concurrent creation and annihilation of periodic orbits in a nonlinear RLC circuit

We have numerically investigated and experimentally demonstrated the presence of antimonotonicity: the concurrent creation and destruction of periodic orbits in a driven nonlinear RLC circuit. A simple manifestation of antimonotonicity is the formation of dimples in a high iterate return map. The evolution of such dimples allows for both contact making and contact breaking homoclinic tangencies of the stable and unstable manifolds. Both numerical and experimental return maps unequivocally exhibit the formation of such dimples. The experimental time series were captured using a 16-bit resolution digitizer allowing for a faithful computation of the high iterate return maps.