High-fidelity Quantum Readout Processing via an Embedded SNAIL Amplifier

TL;DR

This paper introduces an embedded SNAIL amplifier in superconducting quantum readout systems, enabling on-chip, high-fidelity, and scalable quantum-state measurement by integrating amplification and processing directly into the readout architecture.

Contribution

It presents a novel embedded SNAIL platform that allows on-chip, tunable, and coherent quantum readout processing, reducing hardware overhead and enhancing fidelity.

Findings

Enhanced readout fidelity demonstrated through modeling and optimization

Suppressed measurement-induced decoherence in the proposed architecture

Simplified hardware complexity for scalable quantum processors

Abstract

Scalable, high-fidelity quantum-state readout remains a central challenge in the development of large-scale superconducting quantum processors. Conventional dispersive readout architectures depend on bulky isolators and external amplifiers, introducing significant hardware overhead and limiting opportunities for on-chip information processing. In this work, we propose a novel approach that embeds a nonlinear Superconducting Nonlinear Asymmetric Inductive eLement (SNAIL) into the readout chain, enabling coherent and directional processing of readout signals directly on-chip. This embedded SNAIL platform allows frequency-multiplexed resonators to interact through engineered couplings, forming a tunable readout-amplifier-output architecture that can manipulate quantum readout data \textit{in situ}. Through theoretical modeling and numerical optimization, we show that this platform enhances fidelity, suppresses measurement-induced decoherence, and simplifies hardware complexity. These results establish the hybridized SNAIL as a promising building block for scalable and coherent quantum-state readout in next-generation processors.