Superconducting qubits couple strongly to microwave photons and can therefore be coupled over long distances through a superconducting cavity acting as a quantum bus. To avoid frequency-crowding it is desirable to turn qubit coupling off while rearranging qubit frequencies. Here, we present experiments with two gatemon qubits coupled through a cavity, which can be tuned by a voltage-controlled superconducting switch. We characterize the bus tunability and demonstrate switchable qubit coupling with an on/off ratio up to 8. We find that pulsing the bus switch on nanosecond timescales results in the apparent loss of qubit coherence. Further work is needed to understand how dynamic control of the tuneable bus affects qubit operation.
*We acknowledge financial support from Microsoft Project Q, the Danish National Research Foundation and the US Army Research Office
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Authors
Lucas Casparis
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Natalie Pearson
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Anders Kringhøj
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Thorvald Larsen
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Ferdinand Kuemmeth
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Peter Krogstrup
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Jesper Nygard
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Karl Petersson
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
Charles Marcus
Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
