Infinitely coexisting chaotic and nonchaotic attractors in a RLC shunted Josephson Junction with an AC bias current

Josephson Junction (JJ) plays an essential role in superconducting electronics. The Josephson Junction may be classified into different kinds based on the requirements and typically studied under direct bias current. In contrast to prior reports, in this paper, we consider resistive-capacitive-inductance (RLC) shunted Josephson Junction by replacing the direct current as alternating bias current. Using the continuation diagram, we first discuss the stability of equilibrium points. Followed by the dynamical characteristics of such shunted Josephson Junction are explored by varying periodic and quasi-periodic alternating bias currents. We show the periodic bias current exhibits a chaotic behavior while the quasiperiodic bias current displays chaotic as well as strange nonchaotic attractors. We then validated the coexistence of multiple attractors in the parameter space by varying the initial conditions. Finally, the existence of such strange nonchaotic attractors is confirmed using various techniques, such as singularcontinuous spectrum, separation of nearby trajectories, and distribution of finite-time Lyapunov exponents.