Regularising data for practical randomness generation. (14th February 2019)

• Record Type: Journal Article
• Authors: Bourdoncle, Boris; Lin, Pei-Sheng; Rosset, Denis; Acín, Antonio; Liang, Yeong-Cherng
• Is Part Of: Quantum science and technology. Volume 4:Number 2(2019)
• Publication Date: 2019-02-14
• Subjects: Randomness generation -- Bell nonlocality -- device-independent information processing -- quantum information theory; Quantum theory -- Periodicals; Quantum theory; Periodicals; 530
• DOI: 10.1088/2058-9565/ab01e8
• Languages: English
• ISSNs: 2058-9565

Abstract

Abstract: Assuming that the no-signalling principle holds, non-local correlations contain intrinsic randomness. In particular, for a specific Bell experiment, one can derive relations between the amount of randomness produced, as quantified by the min-entropy of the output data, and its associated violation of a Bell inequality. In practice, due to finite sampling, certifying randomness requires the development of statistical tools to lower-bound the min-entropy of the data as a function of the estimated Bell violation. The quality of such bounds relies on the choice of certificate, i.e. the Bell inequality whose violation is estimated. In this work, we propose a method for choosing efficiently such a certificate and analyse, by means of extensive numerical simulations (with various choices of parameters), the extent to which it works. The method requires sacrificing a part of the output data in order to estimate the underlying correlations. Regularising this estimate then allows one to find a Bell inequality that is well suited for certifying practical randomness from these specific correlations. We then study the effects of various parameters on the obtained min-entropy bound and explain how to tune them in a favourable way. Lastly, we carry out several numerical simulations of a Bell experiment to show the efficiency of our method: we nearly always obtain higher min-entropy rates than when we use a pre-established Bell inequality, namely the Clauser–Horne–Shimony–Holt inequality.