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Physical Review A

Robustness of quantum nonclassicality and non-Gaussianity of single-photon states in attenuating channels

Lukáš Lachman, Radim Filip

Published Dec 23, 2013• 24 citations
Publisher

Abstract

We ab initio derive quantum nonclassicality and non-Gaussianity criteria for realistic single-photon sources and discuss the robustness of these quantum features in attenuating quantum channel. The derivation based only on assumptions about the structure of the detector is performed for standard autocorrelation measurement with single-photon detectors. Using both the criteria, we compare the robustness of quantum features of realistic single-photon states with the Poissonian and thermal background noise and discuss a difference between the impact of the multimode structure of thermal noise and truly Poissonian noise.

DOI
10.1103/physreva.88.063841

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We theoretically analyse the relation between non-Gaussianity and security of entanglement-based quantum key distribution (QKD) protocols, namely device-independent (DI) and entanglement-based BB848484. A similar analysis has already been made for prepare-and-measure (P\&M) protocols \cite{Lasota2017}. In addition, we consider imperfect detection with dark counts and limited efficiency. We assume a perfect source of entangled Bell states as produced by quantum-dot type sources, depolarisation in the channel and different noise statistics, namely thermal and Poissonian. We consider single-photon avalanche photodiodes (SPAD) and photon number resolving detectors (PNRD) and use their respective criteria for non-Gaussianity. The results show cross-regions for both security and non-Gaussianity, hence, the possibility to conclude about the suitability of a given channel for secret key distribution. Our results can be useful as a pre-check for the implementation of QKD protocols.
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