Beating the repeaterless bound with adaptive measurement-device-independent quantum key distribution
DATA:
2019-11-26
IDENTIFICADOR UNIVERSAL: http://hdl.handle.net/11093/2274
VERSIÓN EDITADA: https://iopscience.iop.org/article/10.1088/1367-2630/ab54aa
MATERIA UNESCO: 2209.05 Fibras Ópticas ; 3307.07 Dispositivos láser ; 3311.04 Dispositivos Electroópticos ; 3325 Tecnología de las Telecomunicaciones
TIPO DE DOCUMENTO: article
RESUMO
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.