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Protected gates for superconducting qubits

Brooks, Peter and Kitaev, Alexei and Preskill, John (2013) Protected gates for superconducting qubits. Physical Review A, 87 (5). Art. No. 052306. ISSN 1050-2947. doi:10.1103/PhysRevA.87.052306.

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We analyze the accuracy of quantum phase gates acting on “0-π qubits” in superconducting circuits, where the gates are protected against thermal and Hamiltonian noise by continuous-variable quantum error-correcting codes. The gates are executed by turning on and off a tunable Josephson coupling between an LC oscillator and a qubit or pair of qubits; assuming perfect qubits, we show that the gate errors are exponentially small when the oscillator's impedance √L/C is large compared to ℏ/4e^2≈1 kΩ. The protected gates are not computationally universal by themselves, but a scheme for universal fault-tolerant quantum computation can be constructed by combining them with unprotected noisy operations. We validate our analytic arguments with numerical simulations.

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Additional Information:© 2013 American Physical Society Received 21 February 2013; published 6 May 2013. We thank David DiVincenzo for helpful discussions. This work was supported in part by the Intelligence Advanced Research Projects Activity (IARPA) via Department of Interior National Business Center Contract No. D11PC20165. The US government is authorized to reproduce and distribute reprints for governmental purposes notwithstanding any copyright annotation thereon. The views and conclusions contained herein are those of the author and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Intelligence Advanced Research Projects Activity, DoINBC, or the US government. We also acknowledge support from National Science Foundation (NSF) Grant No. PHY-0803371, Department of Energy Grant No. DE-FG03-92-ER40701, and National Security Agency/Army Research Office Grant No. W911NF-09-1-0442. The Institute for Quantum Information and Matter (IQIM) is an NSF Physics Frontiers Center with support from the Gordon and Betty Moore Foundation.
Group:Institute for Quantum Information and Matter, Caltech Theory
Funding AgencyGrant Number
Intelligence Advanced Research Projects Activity (IARPA)UNSPECIFIED
Department of Interior National Business CenterD11PC20165
Department of Energy (DOE)DE-FG03-92-ER40701
National Security Agency (NSA)/Army Research Office (ARO)W911NF-09-1-0442
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
NSF Physics Frontiers CenterUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Issue or Number:5
Classification Code:PACS: 03.67.Pp, 03.67.Lx, 85.25.Hv, 85.25.Cp
Record Number:CaltechAUTHORS:20130619-094717394
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:38982
Deposited By: Tony Diaz
Deposited On:21 Jun 2013 18:20
Last Modified:09 Nov 2021 23:41

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