Benchmarking coherent errors in controlled-phase gates due to spectator qubits

Krinner S, Lazar S, Remm A, Andersen CK, Lacroix N, Norris GJ, Hellings C, Gabureac M, Wallraff A, Eichler C (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Physical Review Applied American Physical Society

Book Volume: 14

Article Number: 024042

Journal Issue: 2

DOI: 10.1103/PhysRevApplied.14.024042

Abstract

A major challenge in operating multiqubit quantum processors is to mitigate multiqubit coherent errors. For superconducting circuits, besides crosstalk originating from imperfect isolation of control lines, dispersive coupling between qubits is a major source of multiqubit coherent errors. We benchmark phase errors in a controlled-phase gate due to dispersive coupling of either of the qubits involved in the gate to one or more spectator qubits. We measure the associated gate infidelity using quantum-process tomography. We point out that, due to coupling of the gate qubits to a noncomputational state during the gate, two-qubit conditional-phase errors are enhanced. Our work is important for understanding limits to the fidelity of two-qubit gates with finite on-off ratio in multiqubit settings.

Authors with CRIS profile

Christopher Eichler

Involved external institutions

Eidgenössische Technische Hochschule Zürich (ETHZ) / Swiss Federal Institute of Technology in Zurich CH Switzerland (CH)

How to cite

APA:

Krinner, S., Lazar, S., Remm, A., Andersen, C.K., Lacroix, N., Norris, G.J.,... Eichler, C. (2020). Benchmarking coherent errors in controlled-phase gates due to spectator qubits. Physical Review Applied, 14(2). https://dx.doi.org/10.1103/PhysRevApplied.14.024042

MLA:

Krinner, S., et al. "Benchmarking coherent errors in controlled-phase gates due to spectator qubits." Physical Review Applied 14.2 (2020).

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