We have fabricated a single Cooper-pair box (SCB) together with an on-chip lumped element resonator. By utilizing the quantum capacitance of the SCB, its state can be read out by detecting the phase of a radio-frequency (rf) signal reflected off the resonator. The resonator was optimized for fast readout. By studying quasiparticle tunneling events in the SCB, we have characterized the performance of the readout and found that we can perform a single shot parity measurement in approximately 50 ns. This is an order of magnitude faster than previously reported measurements.
Assessing Majorana states and qubits through quantum capacitance
Universidade de São Paulo（圣保罗大学）；Consejo Superior de Investigaciones Científicas (CSIC)（西班牙国家研究委员会）；Norwegian University of Science and Technology（挪威科技大学）；Lund University（隆德大学）
Single-shot parity readout of a minimal Kitaev chain
QuTech and Kavli Institute of Nanoscience, Delft University of Technology（代尔夫特理工大学奎克与卡弗里纳米科学研究所）；Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC)（马德里材料科学研究所（ICMM），西班牙高等科学研究委员会（CSIC））；Department of Applied Physics, Eindhoven University of Technology（埃因霍温理工大学应用物理系）
Experimental realization of a $\cos(2φ)$ transmon qubit
Laboratoire de Physique de l’Ecole Normale Supérieure, ENS-PSL, CNRS, Sorbonne Université, Université Paris Cité, Centre Automatique et Systèmes, Mines Paris, Université PSL, Inria（巴黎高等师范学院物理实验室，ENS-PSL，法国国家科学研究中心，索邦大学，巴黎西岱大学，自动化与系统中心，巴黎矿业学院，PSL大学，法国国家信息与自动化研究所）；Google Quantum AI（谷歌量子人工智能）；University of Waterloo（滑铁卢大学）；Laboratoire de Physique Théorique et Hautes Energies, Sorbonne Université and CNRS UMR 7589（理论与高能物理实验室，索邦大学与法国国家科学研究中心联合研究单位7589）
