Selftesting twoqubit maximally entangled states from generalized ClauserHorneShimonyHolt tests
Abstract
Deviceindependent certification, also known as selftesting, aims at guaranteeing the proper functioning of untrusted and uncharacterized devices. For example, the quality of an unknown source expected to produce twoqubit maximally entangled states can be evaluated in a bipartite scenario, each party using two binary measurements. The most robust approach consists in deducing the fidelity of produced states with respect to a twoqubit maximally entangled state from the violation of the CHSH inequality. In this paper, we show how the selftesting of twoqubit 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 selftesting statements can be obtained from correlations that cannot be exploited by a CHSHbased selftesting strategy. Our results not only provide insight into the set of quantum correlations suited for selftesting, but also facilitate the experimental implementations of deviceindependent certifications.
 Publication:

Physical Review Research
 Pub Date:
 January 2022
 DOI:
 10.1103/PhysRevResearch.4.013049
 arXiv:
 arXiv:2011.03047
 Bibcode:
 2022PhRvR...4a3049V
 Keywords:

 Quantum Physics
 EPrint:
 9 pages, 4 figures