@article{12394,
  keywords = {General Physics and Astronomy},
  author = {Eric Rosenthal and Christian Schneider and Maxime Malnou and Ziyi Zhao and Felix Leditzky and Benjamin Chapman and Waltraut Wustmann and Xizheng Ma and Daniel Palken and Maximilian Zanner and Leila Vale and Gene Hilton and Jiansong Gao and Graeme Smith and Gerhard Kirchmair and Konrad Lehnert},
  title = {Efficient and Low-Backaction Quantum Measurement Using a Chip-Scale Detector},
  abstract = {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.},
  year = {2021},
  journal = {Physical Review Letters},
  volume = {126},
  month = {2021-03},
  publisher = {American Physical Society (APS)},
  issn = {0031-9007, 1079-7114},
  url = {https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.126.090503},
  doi = {10.1103/physrevlett.126.090503},
}