2020/08/31 by Eric I. Rosenthal, C. M. F. Schneider, Christian M. F. Schneider +18
Computer Science · Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Amplifier #Electronic engineering #Engineering #Open quantum system #Optoelectronics #Phase qubit #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum computer #Quantum decoherence #Quantum error correction #Quantum mechanics #Quantum network #Quantum sensor #Quantum technology #Qubit #Transmon #quant-ph
paper · pdf · doi:10.1103/physrevlett.126.090503
published as Phys. Rev. Lett. 126, 090503 (2021)
openalex publication_date 2021/03/03 · arxiv created 2021/03/07 · arxiv updated 2021/03/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Superconducting qubits are a leading platform for scalable quantum computing and quantum error correction. One feature of this platform is the ability to perform projective measurements orders of magnitude more quickly than qubit decoherence times. Such measurements are enabled by the use of quantum-limited parametric amplifiers in conjunction with ferrite circulators-magnetic devices which provide isolation from noise and decoherence due to amplifier backaction. Because these nonreciprocal elements have limited performance and are not easily integrated on chip, it has been a long-standing goal to replace them with a scalable alternative. Here, we demonstrate a solution to this problem by using a superconducting switch to control the coupling between a qubit and amplifier. Doing so, we measure a transmon qubit using a single, chip-scale device to provide both parametric amplification and isolation from the bulk of amplifier backaction. This measurement is also fast, high fidelity, and has 70% efficiency, comparable to the best that has been reported in any superconducting qubit measurement. As such, this work constitutes a high-quality platform for the scalable measurement of superconducting qubits.