Self-testing two-qubit maximally entangled states from generalized CHSH tests

Abstract

Device-independent certification, also known as self-testing, aims at guaranteeing the proper functioning of untrusted and uncharacterized devices. For example, the quality of an unknown source expected to produce two-qubit maximally entangled states can be evaluated in a bi-partite scenario, each party using two binary measurements. The most robust approach consists in deducing the fidelity of produced states with respect to a two-qubit maximally entangled state from the violation of the CHSH inequality. In this paper, we show how the self-testing of two-qubit maximally entangled states is improved by a refined analysis of measurement statistics. The use of suitably chosen Bell tests, depending on the observed correlations, allows one to conclude higher fidelities than ones previously known. In particular, nontrivial self-testing statements can be obtained from correlations that cannot be exploited by a CHSH-based self-testing strategy. Our results not only provide novel insight into the set of quantum correlations suited for self-testing, but also facilitate the experimental implementations of device-independent certifications.

arXiv comment9 pages, 4 figures

References in corpus (19)

• Bell nonlocality
• Multidimensional quantum entanglement with large-scale integrated optics
• Self-testing of quantum systems: a review
• Randomness vs Non Locality and Entanglement
• Analytic and nearly optimal self-testing bounds for the Clauser-Horne-Shimony-Holt and Mermin inequalities
• Robust and versatile black-box certification of quantum devices
• Physical characterization of quantum devices from nonlocal correlations
• Device independent state estimation based on Bell's inequalities
• Self-testing of binary observables based on commutation
• All the self-testings of the singlet for two binary measurements
• Certifying the building blocks of quantum computers from Bell's theorem
• Device-independent quantum key distribution with asymmetric CHSH inequalities
• Device-independent quantum key distribution from generalized CHSH inequalities
• Device-independent characterization of quantum instruments
• Experimental investigation of partially entangled states for device-independent randomness generation and self-testing protocols
• Self-testing with finite statistics enabling the certification of a quantum network link
• How post-selection affects device-independent claims under the fair sampling assumption
• Experimental comparison of tomography and self-testing in certifying entanglement
• What is the minimum CHSH score certifying that a state resembles the singlet?

Cited by in corpus (4)

• Device-independent quantum key distribution with arbitrarily small nonlocality
• W-class states-identification and quantification of Bell-CHSH inequalities' violation
• Bounding conditional entropy of bipartite states with Bell operators
• Tight analytic bound on the trade-off between device-independent randomness and nonlocality