Parametric multi-element coupling architecture for coherent and dissipative control of superconducting qubits

As systems for quantum computing keep growing in size and number of qubits,challenges in scaling the control capabilities are becoming increasinglyrelevant. Efficient schemes to simultaneously mediate coherent interactionsbetween multiple quantum systems and to reduce decoherence errors can minimizethe control overhead in next-generation quantum processors. Here, we present asuperconducting qubit architecture based on tunable parametric interactions toperform two-qubit gates, reset, leakage recovery and to read out the qubits. Inthis architecture, parametrically driven multi-element couplers selectivelycouple qubits to resonators and neighbouring qubits, according to the frequencyof the drive. We consider a system with two qubits and one readout resonatorinteracting via a single coupling circuit and experimentally demonstrate acontrolled-Z gate with a fidelity of 98.30± 0.23 %, a reset operation thatunconditionally prepares the qubit ground state with a fidelity of 99.80±0.02 % and a leakage recovery operation with a 98.5± 0.3 % successprobability. Furthermore, we implement a parametric readout with a single-shotassignment fidelity of 88.0± 0.4 %. These operations are all realizedusing a single tunable coupler, demonstrating the experimental feasibility ofthe proposed architecture and its potential for reducing the system complexityin scalable quantum processors.

Further reading#

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