Optimizing the nonlinearity and dissipation of a SNAIL Parametric Amplifier for dynamic range

TL;DR

This paper introduces a tunable, Josephson-junction-based parametric amplifier called the SNAIL Parametric Amplifier (SPA), which can be engineered for optimal nonlinearity and dissipation to enhance dynamic range in quantum applications.

Contribution

It presents a method to engineer and optimize the nonlinearity and port coupling of SNAIL-based amplifiers, improving their saturation power and dynamic range for quantum information processing.

Findings

Engineered nonlinearity over multiple orders of magnitude.

Minimized gain compression and intermodulation distortion.

Achieved higher saturation power without compromising other characteristics.

Abstract

We present a new quantum-limited Josephson-junction-based 3-wave-mixing parametric amplifier, the SNAIL Parametric Amplifier (SPA), which uses an array of SNAILs (Superconducting Nonlinear Asymmetric Inductive eLements) as the source of tunable nonlinearity. We show how to engineer the nonlinearity over multiple orders of magnitude by varying the physical design of the device. As a function of design parameters, we systematically explore two important amplifier nonidealities that limit dynamic range: the phenomena of gain compression and intermodulation distortion, whose minimization are crucial for high-fidelity multi-qubit readout. Through a comparison with first-principles theory across multiple devices, we demonstrate how to optimize both the nonlinearity and the input-output port coupling of these SNAIL-based parametric amplifiers to achieve higher saturation power, without sacrificing any other desirable characteristics. The method elaborated in our work can be extended to improve all forms of parametrically induced mixing that can be employed for quantum information applications.