2014/07/05 by Jean-Luc Orgiazzi, J. -L. Orgiazzi, C. Deng +14 · 2 citations
Computer Science · Physics and Astronomy · #Charge qubit #Circuit quantum electrodynamics #Flux qubit #Phase qubit #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum decoherence #Quantum electrodynamics #Quantum mechanics #Qubit #Superconducting quantum computing #cond-mat.mes-hall #cond-mat.supr-con #quant-ph
paper · pdf · doi:10.1103/physrevb.93.104518
published as Phys. Rev. B 93, 104518 (2016) · 8 pages, including supplementary information
arxiv created 2014/07/05 · openalex publication_date 2016/03/15 · arxiv updated 2016/03/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report experiments on superconducting flux qubits in a circuit quantum electrodynamics (cQED) setup. Two qubits, independently biased and controlled, are coupled to a coplanar waveguide resonator. Dispersive qubit state readout reaches a maximum contrast of 72%. We measure energy relaxation times at the symmetry point of 5 and 10\ensuremathμs, corresponding to 7 and 20\ensuremathμs when relaxation through the resonator due to Purcell effect is subtracted out, and levels of flux noise of 2.6 and 2.7\phantom\rule0.222222em0ex\ensuremathμ\mathrm\ensuremathΦ0/√(Hz) at 1 Hz for the two qubits. We discuss the origin of decoherence in the measured devices. The strong coupling between the qubits and the cavity leads to a large, cavity-mediated, qubit-qubit coupling. This coupling, which is characterized spectroscopically, reaches 38 MHz. These results demonstrate the potential of cQED as a platform for fundamental investigations of decoherence and quantum dynamics of flux qubits.