Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1910.13149 · Physical Review A

Experimental conversion of position correlation into polarization entanglement

Chithrabhanu Perumangatt, Alexander Lohrmann, Alexander Ling

Published Jul 6, 2020• 11 citations
arXivHTMLPDF

Abstract

This paper presents a method to convert position correlation of photon pairs into polarization entanglement. This is achieved by individually manipulating the polarization state of photons generated in different parts of a nonlinear medium and coherently superposing them. This concept is experimentally demonstrated using photon pairs produced by spontaneous parametric down-conversion. The method is used to implement a compact source producing an observed photon-pair rate of $120\phantom{\rule{0.16em}{0ex}}000\phantom{\rule{4.pt}{0ex}}{\text{s}}^{\ensuremath{-}1}/\text{mW}$ with an entanglement fidelity of $0.991\ifmmode\pm\else\textpm\fi{}0.013$. This method can be extended to any photon-pair generation process with initial position correlation.

DOI
10.1103/physreva.102.012404

Related papers

Generation of polarization entanglement utilizing spatially correlated photon pairs from spontaneous parametric down-conversion

T. Yamaguchi, Ryōsuke Shimizu, Yasuyoshi Mitsumori +2 more

Polarization entanglement of photons provides a superior environment to demonstrate quantum info-communication protocols. Thus far, several methods using parametric down-conversion process have been realized to generate polarization-entangled photon pairs. In this report, we propose a novel method to generate polarization entanglement from spatially correlated photon pairs and demonstrate its experimental verification.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2007•0 citations

Conversion of transverse momentum correlation of photon pairs into polarization entanglement by using wavefront-splitting interference

Csaba Tamás Holló, Tamás Sarkadi, Máté Galambos +4 more

The transverse momentum correlation of photon pairs generated by noncollinear spontaneous parametric down-conversion with type-I phase matching is transformed into polarization entanglement. A robust wavefront-splitting interferometer scheme is used, due to which the phase of the entangled state does not require active stabilization. Frequency-degenerate signal and idler photons are separated and coupled into single-mode optical fibers. The concept is demonstrated in a compact and modular setup. A straightforward alignment process for producing any of the Bell states is presented. The entangled source has an output photon flux of $8.33\ifmmode\pm\else\textpm\fi{}1.27$ kcps/mW normalized to pump power (150 mW), and $17\ifmmode\pm\else\textpm\fi{}3%$ heralding ratio. The measured state fidelity with respect to the negative anticorrelated Bell state is $0.951\ifmmode\pm\else\textpm\fi{}0.004$.

Physical Review A•Dec 15, 2022•2 citations

An Ultrafast Source of Polarization Entangled Photon Pairs based on a Sagnac Interferometer

Devin H. Smith

This thesis describes the design, development, and implementation of a pulsed source of polarization-entangled photons using spontaneous parametric down-conversion in a Sagnac interferometer. A tangle of 0.9286 ± 0.0015, fidelity to the state (|10〉 + |01〉)/√2 of \n0.9798 ± 0.0004 and a brightness of 597 pairs/s/mW were demonstrated. \n \nSpontaneous parametric down-conversion is a nonlinear optical process in which one photon is split into two lower-frequency photons while conserving momentum and energy, in this \nexperiment nearly degenerate photons are produced. These photons are then interfered at the output beamsplitter of the interferometer, exchanging path entanglement for polarization entanglement and generating the desired polarization-entangled photon pairs.

•Jan 26, 2009•1 citation

Generation of polarization entanglement from spatially correlated photons in spontaneous parametric down-conversion

Ryōsuke Shimizu, Takashi Yamaguchi, Yasuyoshi Mitsumori +2 more

We propose a scheme to generate polarization entanglement from spatially correlated photon pairs. We experimentally realized a scheme by means of a spatial correlation effect in a spontaneous parametric down-conversion and a modified Michelson interferometer. The scheme we propose in this paper can be interpreted as a conversion process from spatial correlation to polarization entanglement.

arXiv:0711.4177•Physical Review A•Mar 24, 2008•8 citations

Characterization of Entanglement Photons Generated by a Spontaneous Parametric Down-Conversion Pulse Source

Ekkasit Sakatok, Surasak Chiangga

Quantum computation and quantum communication require sources of entangled photons, especially from low-cost diode lasers. This study considered a polarization entangled photons pulse source produced via a spontaneous parametric down-conversion process in the type-I phase-matching of two nonlinear crystals, incorporating a continuous wave laser diode operating in pulse mode as a pump. The generated photons were measured based on visibility as a function of the pump frequency and collection apertures. A polarization correlation between photon pairs of approximately 93% and a Bell parameter S value of 2.56 ± 0.05 were obtained using the source described here.

Agriculture and Natural Resources•Feb 28, 2011•0 citations

Conversion of position correlation into polarization entanglement

Chithrabhanu Perumangatt, Alexander Lohrmann, Alexander Ling

The photon pairs generated by parametric down conversion of a laser beam have inherent position and momentum correlations. We generate polarization entangled photons by manipulating the position correlations using a modified Mach-Zehnder interferometer containing a wedge mirror. The polarization entangled photon pairs exhibit strong quantum correlations and high brightness.

Conference on Lasers and Electro-Optics•May 5, 2019•0 citations
This paper presents a method to convert position correlation of photon pairs into polarization entanglement. This is achieved by individually manipulating the polarization state of photons generated in different parts of a nonlinear medium and coherently superposing them. This concept is experimentally demonstrated using photon pairs produced by spontaneous parametric down-conversion. The method is used to implement a compact source producing an observed photon-pair rate of 120000s\ensuremath−1/mW120\phantom{\rule{0.16em}{0ex}}000\phantom{\rule{4.pt}{0ex}}{\text{s}}^{\ensuremath{-}1}/\text{mW}120000s\ensuremath−1/mW with an entanglement fidelity of 0.991\ifmmode±\else\textpm\fi0.0130.991\ifmmode\pm\else\textpm\fi{}0.0130.991\ifmmode±\else\textpm\fi0.013. This method can be extended to any photon-pair generation process with initial position correlation.
The transverse momentum correlation of photon pairs generated by noncollinear spontaneous parametric down-conversion with type-I phase matching is transformed into polarization entanglement. A robust wavefront-splitting interferometer scheme is used, due to which the phase of the entangled state does not require active stabilization. Frequency-degenerate signal and idler photons are separated and coupled into single-mode optical fibers. The concept is demonstrated in a compact and modular setup. A straightforward alignment process for producing any of the Bell states is presented. The entangled source has an output photon flux of $8.33\ifmmode\pm\else\textpm\fi{}1.27$ kcps/mW normalized to pump power (150 mW), and $17\ifmmode\pm\else\textpm\fi{}3%$ heralding ratio. The measured state fidelity with respect to the negative anticorrelated Bell state is $0.951\ifmmode\pm\else\textpm\fi{}0.004$.
This thesis describes the design, development, and implementation of a pulsed source of polarization-entangled photons using spontaneous parametric down-conversion in a Sagnac interferometer. A tangle of 0.9286 ± 0.0015, fidelity to the state (|10〉 + |01〉)/√2 of \n0.9798 ± 0.0004 and a brightness of 597 pairs/s/mW were demonstrated. \n \nSpontaneous parametric down-conversion is a nonlinear optical process in which one photon is split into two lower-frequency photons while conserving momentum and energy, in this \nexperiment nearly degenerate photons are produced. These photons are then interfered at the output beamsplitter of the interferometer, exchanging path entanglement for polarization entanglement and generating the desired polarization-entangled photon pairs.
Quantum computation and quantum communication require sources of entangled photons, especially from low-cost diode lasers. This study considered a polarization entangled photons pulse source produced via a spontaneous parametric down-conversion process in the type-I phase-matching of two nonlinear crystals, incorporating a continuous wave laser diode operating in pulse mode as a pump. The generated photons were measured based on visibility as a function of the pump frequency and collection apertures. A polarization correlation between photon pairs of approximately 93% and a Bell parameter S value of 2.56 ± 0.05 were obtained using the source described here.