Beating the repeaterless bound with adaptive measurement-device-independent quantum key distribution. (26th November 2019)

• Record Type: Journal Article
• Authors: Trényi, Róbert; Azuma, Koji; Curty, Marcos
• Is Part Of: New journal of physics. Volume 21:Number 11(2019:Nov.)
• Publication Date: 2019-11-26
• Subjects: quantum key distribution -- repeaterless bound -- quantum communications -- quantum cryptography -- measurement-device-independent; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ab54aa
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: Surpassing the repeaterless bound is a crucial task on the way towards realizing long-distance quantum key distribution. In this paper, we focus on the protocol proposed by Azuma et al (2015 Nat. Commun. 6 10171), which can beat this bound with idealized devices. We investigate the robustness of this protocol against imperfections in realistic setups, particularly the multiple-photon pair components emitted by practical entanglement sources. In doing so, we derive necessary conditions on the photon-number statistics of the sources in order to beat the repeaterless bound. We show, for instance, that parametric down-conversion sources do not satisfy the required conditions and thus cannot be used to outperform this bound.