2020/11/18 by I. Takmakov, Ivan Takmakov, Patrick Winkel +21
Computer Science · Physics and Astronomy · #Amplifier #Amplitude #Atom (system on chip) #Bandwidth (computing) #Cold Atom Physics and Bose-Einstein Condensates #Mechanical and Optical Resonators #Photon #Quantum #Quantum Information and Cryptography #Quantum computer #Quantum error correction #Quantum sensor #Quantum state #cond-mat.supr-con #quant-ph
paper · pdf · doi:10.1103/physrevapplied.15.064029
published as Phys. Rev. Applied 15, 064029 (2021) · main text: 5 pages + 4 figures. appendices: 3 pages + 3 figures
arxiv created 2020/11/18 · openalex created_date 2020/11/23 · openalex publication_date 2021/06/11 · arxiv updated 2021/06/16 · openalex updated_date 2026/08/05
Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal-field amplitude in the readout resonator, dispersively coupled to the artificial atom, improves the signal-to-noise ratio and increases the measurement strength. Here, we employ this effect over 2 orders of magnitude in readout power, made possible by the unique combination of a dimer-Josephson-junction-array amplifier with a large dynamic range and the fact that the readout of our granular aluminum fluxonium artificial atom remains quantum nondemolition (QND) at relatively large photon numbers in the readout resonator, up to n=110. Using Bayesian inference, this allows us to detect quantum jumps faster than the readout-resonator response time 2/\ensuremathκ, where \ensuremathκ is the bandwidth of the readout resonator.