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arXiv · 2402.19435

Simple, High Saturation Power, Quantum-limited, RF SQUID Array-based Josephson Parametric Amplifiers

Ryan Kaufman·Chenxu Liu·Katarina Cicak·Boris Mesits·Mingkang Xia·Chao Zhou·Maria Nowicki·José Aumentado·David Pekker·Michael Hatridge
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Abstract

High-fidelity quantum non-demolition qubit measurement is critical to error correction and rapid qubit feedback in large-scale quantum computing. High-fidelity readout requires passing a short and strong pulse through the qubit's readout resonator, which is then processed by a sufficiently high bandwidth, high saturation power, and quantum-limited amplifier. We have developed a design pipeline that combines time-domain simulation of the un-truncated device Hamiltonian, fabrication constraints, and maximization of saturation power. We have realized an amplifier based on a modified NIST tri-layer Nb fabrication suite which utilizes an array of 25 radio frequency Superconducting QUantum Interference Devices (rf SQUIDs) embedded within a low-Q resonator powered by a high-power voltage pump delivered via a diplexer on the signal port. We show that, despite the intensity of the pump, the device is quantum-efficient and capable of high-fidelity measurement limited by state transitions in the transmon. We present experimental data demonstrating up to -91.2 dBm input saturation power with 20 dB gain, up to 28 MHz instantaneous bandwidth, and phase-preserving qubit measurements with 62% quantum efficiency.

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Ryan Kaufman, Chenxu Liu, Katarina Cicak, Boris Mesits, Mingkang Xia, Chao Zhou, Maria Nowicki, José Aumentado, David Pekker, Michael Hatridge. 2024-05-21. Simple, High Saturation Power, Quantum-limited, RF SQUID Array-based Josephson Parametric Amplifiers. https://arxiv.org/abs/2402.19435

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