Detecting highly entangled states with a joint qubit readout

Journal Article · Tue Jun 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.062325· OSTI ID:21407921

Chow, J M; DiCarlo, L; Nunnenkamp, A; Bishop, Lev S; Frunzio, L; Devoret, M H; Girvin, S M; Schoelkopf, R J ^[1]; Gambetta, J M ^[2]

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1. Departments of Physics and Applied Physics, Yale University, New Haven, Connecticut 06520 (United States)
2. Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

A single-channel joint readout is used to analyze highly entangled two-qubit states in a circuit quantum electrodynamics architecture. The measurement model for the readout is fully characterized, demonstrating a large sensitivity to two-qubit correlations. We quantify the high degree of entanglement by measuring a violation of the Clauser-Horne-Shimony-Holt inequality with a value of 2.61{+-}0.04, without optimizing the preparation of the two-qubit state. In its present form, this joint readout can resolve improvements to the fidelity of two-qubit operations and be extended to three or four qubits.

• OSTI ID: 21407921
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 81; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CORRELATIONS
ELECTRODYNAMICS
FIELD THEORIES
INFORMATION
OPTIMIZATION
QUANTUM ELECTRODYNAMICS
QUANTUM ENTANGLEMENT
QUANTUM FIELD THEORY
QUANTUM INFORMATION
QUBITS
READOUT SYSTEMS
SENSITIVITY