A new device-independent dimension witness and its experimental implementation. (20th June 2016)

• Record Type: Journal Article
• Authors: Cai, Yu; Bancal, Jean-Daniel; Romero, Jacquiline; Scarani, Valerio
• Is Part Of: Journal of physics. Volume 49:Number 30(2016)
• Publication Date: 2016-06-20
• Subjects: dimension witness -- device independent -- Bell inequality -- high dimension entanglement; Mathematical physics -- Periodicals; Statistical physics -- Periodicals; Quantum theory -- Periodicals; Matter -- Properties -- Periodicals; 530.105
• DOI: 10.1088/1751-8113/49/30/305301
• Languages: English
• ISSNs: 1751-8113

Abstract

Abstract: A dimension witness is a criterion that sets a lower bound on the dimension needed to reproduce the observed data. Three types of dimension witnesses can be found in the literature: device-dependent ones, in which the bound is obtained assuming some knowledge on the state and the measurements; device-independent prepare-and-measure ones, that can be applied to any system including classical ones; and device-independent Bell-based ones, that certify the minimal dimension of some entangled systems. Here we consider the Collins–Gisin–Linden–Massar–Popescu Bell-type inequality for four outcomes. We show that a sufficiently high violation of this inequality witnesses d ≥ 4 and present a proof-of-principle experimental observation of such a violation. This presents a first experimental violation of the third type of dimension witness beyond qutrits.