Nicolas Brunner

TL;DR: The main result is a tight bound on the Holevo information between one of the authorized parties and the eavesdropper, as a function of the amount of violation of a Bell-type inequality.

TL;DR: This proof exploits the full structure of quantum theory, but only holds against collective attacks, where the eavesdropper is assumed to act on the quantum systems of the honest parties independently and identically in each round of the protocol.

TL;DR: In this paper, the authors present a source of entangled photons that violates a Bell inequality free of the fair sampling assumption, by over 7 standard deviations, and demonstrate enough overhead to eventually perform a fully loophole-free test of local realism.

TL;DR: It is shown that standard interferometry greatly outperforms weak measurements in a scenario involving a purely real weak value, but an interferometric scheme based on a purely imaginary weak value combined with a frequency-domain analysis may have the potential to outperform standardInterferometry by several orders of magnitude.

TL;DR: The concept of dimension witness is introduced to put lower bounds on d, the minimal dimension necessary to describe correlations in Hilbert space dimension, in various contexts related to fundamental questions and quantum information applications.