Coherent coupling of long-distance spins is a crucial step towards quantum information processing with spin-qubits. We use a circuit quantum electrodynamics architecture to demonstrate strong coupling between single microwave photons in a high impedance NbTiN cavity and a three-electron spin-qubit in a GaAs triple quantum dot. We resolve the vacuum Rabi mode splitting with a coupling strength of g/2π≈31MHz and a qubit decoherence rate of γ2/2π≈20MHz. The spin-qubit is formed by exchange interaction, which couples the spin with the orbital degrees of freedom. We can directly access the amount of spin-charge coupling strength electrostatically. This allows us to tune both the qubit-photon coupling strength as well as the qubit decoherence. From dispersive two-tone spectroscopy measurements we extract a minimum qubit decoherence rate of γ2/2π≈10MHz for a coupling strength of g/2π≈23MHz. We also observe an ac Stark shift of the qubit frequency, which allows us to calibrate the number of photons in the resonator and gives direct access to the qubit-photon coupling strength.
*This work was supported by the Swiss National Science Foundation through the NCCR Quantum Science and Technology. U.C.M. and A.B. were supported by NSERC and the Canada First Research Excellence fund.
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Presenters
Andreas Landig
ETH - Zurich
Physics, ETH Zurich
Department of Physics, ETH Zurich
Authors
Andreas Landig
ETH - Zurich
Physics, ETH Zurich
Department of Physics, ETH Zurich
Jonne Koski
ETH - Zurich
ETH Zurich
Physics, ETH Zurich
Department of Physics, ETH Zurich
Pasquale Scarlino
ETH - Zurich
Delft University of Technology
Physics, ETH Zurich
Department of Physics, ETH Zurich
Udson Mendes
Institut quantique and Department de Physique, Universite de Sherbrooke
Physics, University of Sherbrooke
Institut quantique and Départment de Physique, Université de Sherbrooke
Alexandre Blais
Institut quantique and Departement de Physique, Universite de Sherbrooke
Physique, Institut Quantique
University of Sherbrooke
Institut quantique and Department de Physique, Universite de Sherbrooke
Physique, Universite de Sherbrooke
Physics, University of Sherbrooke
Institut quantique and Départment de Physique, Université de Sherbrooke
Institut Quantique and Département de Physique, Université de Sherbrooke
Univ of Sherbrooke
Institut Quantique and Département de Physique, Université de Sherbooke
Institut quantique and Département de Physique, Université de Sherbrooke
