Driving a Josephson Traveling Wave Parametric Amplifier into chaos: effects of a non-sinusoidal current-phase relation

TL;DR

This paper investigates the dynamic behavior of Josephson Traveling Wave Parametric Amplifiers, especially the transition to chaos influenced by non-sinusoidal current-phase relations, providing insights for improved device stability and performance.

Contribution

It offers a comprehensive numerical analysis of chaos pathways in JTWPAs and explores the effects of non-sinusoidal CPR on their operation, advancing understanding of their nonlinear dynamics.

Findings

Identification of chaos transition pathways in JTWPAs

Impact of non-sinusoidal CPR on gain and stability

Guidelines for optimizing device design against chaos

Abstract

In this work, we develop a comprehensive numerical analysis of the dynamic response of a Josephson Traveling Wave Parametric Amplifier (JTWPA) by varying the driving parameters, with a focus on the pathways leading to chaotic behavior. By tuning the working conditions, we capture the broad spectrum of dynamical regimes accessible to JTWPAs, delineating the settings under which transition to chaos occurs. Furthermore, we extend our investigation to device formed by junctions characterized by a non--sinusoidal current phase relation (CPR) and exploring the impact of its shape on the amplifier's performance. Through the study of gain characteristics, Poincar\'e sections, and Fourier spectra, we provide an in-depth understanding of how non-linearity and CPR nonsinusoidality influence the JTWPAs' operational effectiveness and stability. This investigation offers insights into optimizing the device designs for enhanced performance and robustness against chaotic disruptions, in order to establish a framework for predicting and controlling JTWPA behavior in practical applications. This effort will pave the way for the development of devices with tailored dynamic responses and for advancements in quantum computing and precision measurement technologies, where stability and high fidelity are of paramount importance.