Fast parametric two-qubit gates with suppressed residual interaction using a parity-violated superconducting qubit

• URL: http://arxiv.org/abs/2005.02630v2
• Date: Thu, 7 May 2020 07:22:47 GMT
• Title: Fast parametric two-qubit gates with suppressed residual interaction using a parity-violated superconducting qubit
• Authors: Atsushi Noguchi, Alto Osada, Shumpei Masuda, Shingo Kono, Kentaro Heya, Samuel Piotr Wolski, Hiroki Takahashi, Takanori Sugiyama, Dany Lachance-Quirion, Yasunobu Nakamura
• Abstract summary: Two-qubit gates are demonstrated using a superconducting qubit consisting of a capacitively-shunted asymmetric Josephson-junction loop under a finite magnetic flux bias. The average fidelities of the two-qubit gates are evaluated with randomized benchmarking frequencies as 0.967, 0.951, 0.956 for CZ, iSWAP and SWAP gates, respectively.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We demonstrate fast two-qubit gates using a parity-violated superconducting qubit consisting of a capacitively-shunted asymmetric Josephson-junction loop under a finite magnetic flux bias. The second-order nonlinearity manifesting in the qubit enables the interaction with a neighboring single-junction transmon qubit via first-order inter-qubit sideband transitions with Rabi frequencies up to 30~MHz. Simultaneously, the unwanted static longitudinal~(ZZ) interaction is eliminated with ac Stark shifts induced by a continuous microwave drive near-resonant to the sideband transitions. The average fidelities of the two-qubit gates are evaluated with randomized benchmarking as 0.967, 0.951, 0.956 for CZ, iSWAP and SWAP gates, respectively.

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