In this work, the addition of a filtering resonator to protect against Purcell decay in the surface code implementation presented in [R. Versluis et al., 2017, Phys. Rev. Applied] is investigated.The requirements on single- and two-qubit gate operation as well as readout is outli
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In this work, the addition of a filtering resonator to protect against Purcell decay in the surface code implementation presented in [R. Versluis et al., 2017, Phys. Rev. Applied] is investigated.The requirements on single- and two-qubit gate operation as well as readout is outlined. We model the system with differential equations to optimize the coupling strengths and target frequencies for fast readout and minimized dephasing of untargeted qubits. The currently used qubit design is adapted to achieve these goals. A proof-of-concept chip, containing a subset of the surface code is implemented using these altered qubits, fabricated and characterized.On this device, state-of-the art readout fidelities of >98% within 450 ns are demonstrated. Back-action on untargeted qubits is measured and an upper bound is determined.
