Robust and versatile black-box certification of quantum devices

Abstract

Self-testing refers to the fact that, in some quantum devices, both states and measurements can be assessed in a black-box scenario, on the sole basis of the observed statistics, i.e. without reference to any prior device calibration. Only a few examples of self-testing are known, and they just provide non-trivial assessment for devices performing unrealistically close to the ideal case. We overcome these difficulties by approaching self-testing with the semi-definite programming hierarchy for the characterization of quantum correlations. This allows us to improve dramatically the robustness of previous self-testing schemes -e.g.: we show that a CHSH violation larger than 2.57 certifies a singlet fidelity of more than 70%. In addition, the versatility of the tool brings about self-testing of hitherto impossible cases, such as robust self-testing of non-maximally entangled two-qutrit states in the CGLMP scenario.

4 pages, 4 figures, 1 appendix

References in corpus (5)

• Device-independent security of quantum cryptography against collective attacks
• Bounding the set of quantum correlations
• Measuring measurement
• Private Randomness Expansion With Untrusted Devices
• Robust Self Testing of the Singlet

Cited by in corpus (7)

• Robust self testing of the 3-qubit $W$ state
• Device-independent tomography of multipartite quantum states
• Efficient tomography with unknown detectors
• Data-pattern tomography of entangled states
• When quantum state tomography benefits from willful ignorance
• Self-testing of symmetric three-qubit states
• Optimal Verification of the Bell State and Greenberger-Horne-Zeilinger States in Untrusted Quantum Networks