Rate-distance tradeoff and resource costs for all-optical quantum repeaters

Mihir Pant, Hari Krovi, Dirk Englund, Saikat Guha

Research output: Contribution to journalArticle

42 Scopus citations

Abstract

We present a resource-performance tradeoff of an all-optical quantum repeater that uses photon sources, linear optics, photon detectors, and classical feedforward at each repeater node, but no quantum memories. We show that the quantum-secure key rate has the form R(η)=Dηs bits per mode, where η is the end-to-end channel's transmissivity, and the constants D and s are functions of various device inefficiencies and the resource constraint, such as the number of available photon sources at each repeater node. Even with lossy devices, we show that it is possible to attain s<1, and in turn outperform the maximum key rate attainable without quantum repeaters, Rdirect(η)=-log2(1-η)≈(1/ln2)η bits per mode for η1, beyond a certain total range L, where η∼e-αL in optical fiber. We also propose a suite of modifications to a recently proposed all-optical repeater protocol that ours builds upon, which lower the number of photon sources required to create photonic clusters at the repeaters so as to outperform Rdirect(η), from ∼1011 to ∼106 photon sources per repeater node. We show that the optimum separation between repeater nodes is independent of the total range L and is around 1.5 km for assumptions we make on various device losses.

Original languageEnglish (US)
Article number012304
JournalPhysical Review A
Volume95
Issue number1
DOIs
StatePublished - Jan 4 2017
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Rate-distance tradeoff and resource costs for all-optical quantum repeaters'. Together they form a unique fingerprint.

Cite this