Abstract

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 quasi-periodic 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 singular-continuous spectrum, separation of nearby trajectories, and distribution of finite-time Lyapunov exponents.

Graphic abstract

中文翻译：

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具有交流偏置电流的 RLC 分流约瑟夫森结中无限共存的混沌和非混沌吸引子

摘要

约瑟夫森结 (JJ) 在超导电子学中起着至关重要的作用。约瑟夫森结可以根据需要分为不同的种类，通常在直流偏置电流下进行研究。与之前的报道相比，在本文中，我们通过将直流电替换为交流偏置电流来考虑电阻-电容-电感 (RLC) 分流约瑟夫森结。使用延拓图，我们首先讨论平衡点的稳定性。其次通过改变周期性和准周期性交变偏置电流来探索这种分流约瑟夫森结的动态特性。我们展示了周期性偏置电流表现出混沌行为，而准周期性偏置电流表现出混沌以及奇怪的非混沌吸引子。然后，我们通过改变初始条件验证了参数空间中多个吸引子的共存。最后，使用各种技术证实了这种奇怪的非混沌吸引子的存在，例如奇异连续谱、附近轨迹的分离以及有限时间李雅普诺夫指数的分布。

图形摘要