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Title: Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium

Abstract

We propose a setup for a heralded, i.e., announced generation of a pure single-photon state given two imperfect sources whose outputs are represented by mixtures of the single-photon Fock state [1> with the vacuum [0>. Our purification scheme uses beam splitters, photodetection, and a two-photon-absorbing medium. The admixture of the vacuum is fully eliminated. We discuss two potential realizations of the scheme.

Authors:
; ; ;  [1]
  1. Fachbereich Physik, Universitaet Konstanz, D-78457 Constance (Germany)
Publication Date:
OSTI Identifier:
20786876
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.73.032327; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ENERGY LEVELS; MIXTURES; MULTI-PHOTON PROCESSES; OPTICS; PHOTONS; QUANTUM MECHANICS

Citation Formats

Konrad, Thomas, Scherer, Artur, Nock, Michael, and Audretsch, Juergen. Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium. United States: N. p., 2006. Web. doi:10.1103/PHYSREVA.73.0.
Konrad, Thomas, Scherer, Artur, Nock, Michael, & Audretsch, Juergen. Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium. United States. doi:10.1103/PHYSREVA.73.0.
Konrad, Thomas, Scherer, Artur, Nock, Michael, and Audretsch, Juergen. Wed . "Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium". United States. doi:10.1103/PHYSREVA.73.0.
@article{osti_20786876,
title = {Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium},
author = {Konrad, Thomas and Scherer, Artur and Nock, Michael and Audretsch, Juergen},
abstractNote = {We propose a setup for a heralded, i.e., announced generation of a pure single-photon state given two imperfect sources whose outputs are represented by mixtures of the single-photon Fock state [1> with the vacuum [0>. Our purification scheme uses beam splitters, photodetection, and a two-photon-absorbing medium. The admixture of the vacuum is fully eliminated. We discuss two potential realizations of the scheme.},
doi = {10.1103/PHYSREVA.73.0},
journal = {Physical Review. A},
number = 3,
volume = 73,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • Realistic single-photon sources do not generate single photons with certainty. Instead they produce statistical mixtures of photons in Fock states |1> and vacuum (noise). We describe how to eliminate the noise in the output of the sources by means of another noisy source or a coherent state and cross-phase-modulation (XPM). We present a scheme that announces the production of pure single photons and thus eliminates the vacuum contribution. This is done by verifying a XPM-related phase shift with a Mach-Zehnder interferometer.
  • We derive calculations on the statistics of a heralded single-photon source based on parametric photon-pair generation. These calculations highlight fundamental and practical limits for these sources and show which physical parameters can be optimized to improve the quality of a real source.
  • A recent Brief Report [Phys. Rev. A 79, 035801 (2009)] investigates two figures of merit for heralded photon sources based on spontaneous parametric down-conversion with a continuous pump, namely, the time-averaged temporal coherence between the signal and idler beams and the time-averaged conditioned second-order degree of coherence for photons in the heralded arm. However, contrary to what is claimed, no one-arm second-order effect is actually measured.
  • Recently a long distance and high key rate quantum key distribution (QKD) has become possible by the idea of the decoy state method. We show that a longer distance QKD is possible by utilizing a heralded single photon source (utilizing spontaneous parametric down-conversion) as a source instead of a weak coherent pulse (WCP) as proposed in the original decoy state method. Moreover, the key rate is improved by utilizing a presently available photon number resolving detector as a trigger detector of the heralded single photon source and it is shown to approach the key rate of the WCP.
  • For the Bennett-Brassard 1984 (BB84) quantum key distribution, longer distance and higher key generating rate is shown with a heralded single-photon source (HSPS) [Phys. Rev. A. 73, 032331 (2006)]. In this paper, the performance of the Scarani-Acin-Ribordy-Gisim (SARG) protocol utilizing the HSPS sources is considered and the numerical simulation turns out that still a significant improvement in secret key generating rate can also be observed. It is shown that the security distance for HSPS+SARG is 120 km. However, compared with the HSPS+BB84 protocols, the HSPS+SARG protocol has a lower secret key rate and a shorter distance. Thus we show themore » HSPS+BB84 implementation is a preferable protocol for long distance transmittance.« less