title: Gatemon Benchmarking and Two-Qubit Operations.
abstract: Recent experiments have demonstrated superconducting transmon qubits with semiconductor nanowire Josephson junctions. These hybrid gatemon qubits utilize field effect tunability characteristic of semiconductors to allow complete qubit control using gate voltages, potentially a technological advantage over conventional flux-controlled transmons. Here, we present experiments with a two-qubit gatemon circuit. We characterize qubit coherence and stability and use randomized benchmarking to demonstrate single-qubit gate errors below 0.7% for all gates, including voltage-controlled Z rotations. We show coherent capacitive coupling between two gatemons and coherent swap operations. Finally, we perform a two-qubit controlled-phase gate with an estimated fidelity of 91%, demonstrating the potential of gatemon qubits for building scalable quantum processors.
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Casparis
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: T W
authors.initials: TW
authors.lastname: Larsen
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: M S
authors.initials: MS
authors.lastname: Olsen
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: F
authors.initials: F
authors.lastname: Kuemmeth
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Krogstrup
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.|Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Nygård
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: K D
authors.initials: KD
authors.lastname: Petersson
authors.affiliation: Center for Quantum Devices, Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Copenhagen DK-2100, Denmark.
authors.forename: C M
authors.initials: CM
authors.lastname: Marcus