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Gao X, Zhang Y, D'Errico A, Hufnagel F, Heshami K, Karimi E. Manipulating the symmetry of transverse momentum entangled biphoton states. OPTICS EXPRESS 2022; 30:21276-21281. [PMID: 36224850 DOI: 10.1364/oe.458776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/10/2022] [Indexed: 06/16/2023]
Abstract
Bell states are a fundamental resource in photonic quantum information processing. These states have been generated successfully in many photonic degrees of freedom. Their manipulation, however, in the momentum space remains challenging. Here, we present a scheme for engineering the symmetry of two-photon states entangled in the transverse momentum degree of freedom through the use of a spatially variable phase object. We demonstrate how a Hong-Ou-Mandel interferometer must be constructed to verify the symmetry in momentum entanglement via photon "bunching/anti-bunching" observation. We also show how this approach allows generating states that acquire an arbitrary phase under the exchange operation.
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2
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Lum DJ, Mazurek MD, Mikhaylov A, Parzuchowski KM, Wilson RN, Jimenez R, Gerrits T, Stevens MJ, Cicerone MT, Camp CH. Witnessing the survival of time-energy entanglement through biological tissue and scattering media. BIOMEDICAL OPTICS EXPRESS 2021; 12:3658-3670. [PMID: 34221686 PMCID: PMC8221931 DOI: 10.1364/boe.423743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate the preservation of the time-energy entanglement of near-IR photons through thick biological media (≤1.55 mm) and tissue (≤ 235 μm) at room temperature. Using a Franson-type interferometer, we demonstrate interferometric contrast of over 0.9 in skim milk, 2% milk, and chicken tissue. This work supports the many proposed opportunities for nonclassical light in biological imaging and analyses from sub-shot noise measurements to entanglement-enhanced fluorescence imaging, clearly indicating that the entanglement characteristics of photons can be maintained even after propagation through thick, turbid biological samples.
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Affiliation(s)
- Daniel J. Lum
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Michael D. Mazurek
- Department of Physics, University of Colorado, Boulder CO 80309, USA
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | | | - Kristen M. Parzuchowski
- Department of Physics, University of Colorado, Boulder CO 80309, USA
- JILA, 440 UCB, University of Colorado, Boulder, CO 80309, USA
| | - Ryan N. Wilson
- Department of Physics, University of Colorado, Boulder CO 80309, USA
- JILA, 440 UCB, University of Colorado, Boulder, CO 80309, USA
| | - Ralph Jimenez
- JILA, 440 UCB, University of Colorado, Boulder, CO 80309, USA
- Department of Chemistry, 215 UCB, University of Colorado, Boulder, CO 80309, USA
| | - Thomas Gerrits
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Martin J. Stevens
- National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - Marcus T. Cicerone
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Charles H. Camp
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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3
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Anwar A, Perumangatt C, Steinlechner F, Jennewein T, Ling A. Entangled photon-pair sources based on three-wave mixing in bulk crystals. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:041101. [PMID: 34243479 DOI: 10.1063/5.0023103] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 03/01/2021] [Indexed: 06/13/2023]
Abstract
Entangled photon pairs are a critical resource in quantum communication protocols ranging from quantum key distribution to teleportation. The current workhorse technique for producing photon pairs is via spontaneous parametric down conversion (SPDC) in bulk nonlinear crystals. The increased prominence of quantum networks has led to a growing interest in deployable high performance entangled photon-pair sources. This manuscript provides a review of the state-of-the-art bulk-optics-based SPDC sources with continuous wave pump and discusses some of the main considerations when building for deployment.
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Affiliation(s)
- Ali Anwar
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, S117543 Singapore, Singapore
| | - Chithrabhanu Perumangatt
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, S117543 Singapore, Singapore
| | - Fabian Steinlechner
- Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Straße 7, 07745 Jena, Germany
| | - Thomas Jennewein
- Institute of Quantum Computing and Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
| | - Alexander Ling
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, S117543 Singapore, Singapore
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4
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Vedovato F, Agnesi C, Tomasin M, Avesani M, Larsson JÅ, Vallone G, Villoresi P. Postselection-Loophole-Free Bell Violation with Genuine Time-Bin Entanglement. PHYSICAL REVIEW LETTERS 2018; 121:190401. [PMID: 30468593 DOI: 10.1103/physrevlett.121.190401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/11/2018] [Indexed: 06/09/2023]
Abstract
Entanglement is an invaluable resource for fundamental tests of physics and the implementation of quantum information protocols such as device-independent secure communications. In particular, time-bin entanglement is widely exploited to reach these purposes both in free space and optical fiber propagation, due to the robustness and simplicity of its implementation. However, all existing realizations of time-bin entanglement suffer from an intrinsic postselection loophole, which undermines their usefulness. Here, we report the first experimental violation of Bell's inequality with "genuine" time-bin entanglement, free of the postselection loophole. We introduced a novel function of the interferometers at the two measurement stations, that operate as fast synchronized optical switches. This scheme allowed us to obtain a postselection-loophole-free Bell violation of more than 9 standard deviations. Since our scheme is fully implementable using standard fiber-based components and is compatible with modern integrated photonics, our results pave the way for the distribution of genuine time-bin entanglement over long distances.
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Affiliation(s)
- Francesco Vedovato
- Dipartimento di Ingegneria dell'Informazione, Università di Padova, via Gradenigo 6B, 35131 Padova, Italy
- Centro di Ateneo di Studi e Attività Spaziali "G. Colombo", Università di Padova, via Venezia 15, 35131 Padova, Italy
| | - Costantino Agnesi
- Dipartimento di Ingegneria dell'Informazione, Università di Padova, via Gradenigo 6B, 35131 Padova, Italy
| | - Marco Tomasin
- Dipartimento di Ingegneria dell'Informazione, Università di Padova, via Gradenigo 6B, 35131 Padova, Italy
| | - Marco Avesani
- Dipartimento di Ingegneria dell'Informazione, Università di Padova, via Gradenigo 6B, 35131 Padova, Italy
| | - Jan-Åke Larsson
- Institutionen för systemteknik, Linköping Universitet, 581 83 Linköping, Sweden
| | - Giuseppe Vallone
- Dipartimento di Ingegneria dell'Informazione, Università di Padova, via Gradenigo 6B, 35131 Padova, Italy
- Istituto di Fotonica e Nanotecnologie, CNR, via Trasea 7, 35131 Padova, Italy
| | - Paolo Villoresi
- Dipartimento di Ingegneria dell'Informazione, Università di Padova, via Gradenigo 6B, 35131 Padova, Italy
- Istituto di Fotonica e Nanotecnologie, CNR, via Trasea 7, 35131 Padova, Italy
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5
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Ihn YS, Kim Y, Tamma V, Kim YH. Second-Order Temporal Interference with Thermal Light: Interference beyond the Coherence Time. PHYSICAL REVIEW LETTERS 2017; 119:263603. [PMID: 29328723 DOI: 10.1103/physrevlett.119.263603] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Indexed: 06/07/2023]
Abstract
We report the observation of a counterintuitive phenomenon in multipath correlation interferometry with thermal light. The intensity correlation between the outputs of two unbalanced Mach-Zehnder interferometers (UMZIs) with two classically correlated beams of thermal light at the input exhibits genuine second-order interference with the visibility of 1/3. Surprisingly, the second-order interference does not degrade at all no matter how much the path length difference in each UMZI is increased beyond the coherence length of the thermal light. Moreover, the second-order interference is dependent on the difference of the UMZI phases. These results differ substantially from those of the entangled-photon Franson interferometer, which exhibits two-photon interference dependent on the sum of the UMZI phases and the interference vanishes as the path length difference in each UMZI exceeds the coherence length of the pump laser. Our work offers deeper insight into the interplay between interference and coherence in multiphoton interferometry.
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Affiliation(s)
- Yong Sup Ihn
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Yosep Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Vincenzo Tamma
- Faculty of Science, SEES and Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3QL, United Kingdom
| | - Yoon-Ho Kim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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6
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Steinlechner F, Ecker S, Fink M, Liu B, Bavaresco J, Huber M, Scheidl T, Ursin R. Distribution of high-dimensional entanglement via an intra-city free-space link. Nat Commun 2017; 8:15971. [PMID: 28737168 PMCID: PMC5527279 DOI: 10.1038/ncomms15971] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 05/17/2017] [Indexed: 11/09/2022] Open
Abstract
Quantum entanglement is a fundamental resource in quantum information processing and its distribution between distant parties is a key challenge in quantum communications. Increasing the dimensionality of entanglement has been shown to improve robustness and channel capacities in secure quantum communications. Here we report on the distribution of genuine high-dimensional entanglement via a 1.2-km-long free-space link across Vienna. We exploit hyperentanglement, that is, simultaneous entanglement in polarization and energy-time bases, to encode quantum information, and observe high-visibility interference for successive correlation measurements in each degree of freedom. These visibilities impose lower bounds on entanglement in each subspace individually and certify four-dimensional entanglement for the hyperentangled system. The high-fidelity transmission of high-dimensional entanglement under real-world atmospheric link conditions represents an important step towards long-distance quantum communications with more complex quantum systems and the implementation of advanced quantum experiments with satellite links. Increasing the dimensionality of entangled states improves robustness and capacity of secure quantum communications, but it requires suitably modified setups. Here the authors report the distribution of high-dimensional polarization and energy-time entangled photons via a 1.2 km-long free-space link.
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Affiliation(s)
- Fabian Steinlechner
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Sebastian Ecker
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Matthias Fink
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Bo Liu
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria.,School of Computer, NUDT, Changsha 410073, China
| | - Jessica Bavaresco
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Marcus Huber
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Thomas Scheidl
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria
| | - Rupert Ursin
- Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria.,Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
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7
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Two-photon interference of polarization-entangled photons in a Franson interferometer. Sci Rep 2017; 7:5772. [PMID: 28720885 PMCID: PMC5516045 DOI: 10.1038/s41598-017-06196-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/07/2017] [Indexed: 11/25/2022] Open
Abstract
We present two-photon interference experiments with polarization-entangled photon pairs in a polarization-based Franson-type interferometer. Although the two photons do not meet at a common beamsplitter, a phase-insensitive Hong-Ou-Mandel type two-photon interference peak and dip fringes are observed, resulting from the two-photon interference effect between two indistinguishable two-photon probability amplitudes leading to a coincidence detection. A spatial quantum beating fringe is also measured for nondegenerate photon pairs in the same interferometer, although the two-photon states have no frequency entanglement. When unentangled polarization-correlated photons are used as an input state, the polarization entanglement is successfully recovered through the interferometer via delayed compensation.
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8
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Complete hyperentangled-Bell-state analysis for photonic qubits assisted by a three-level Λ-type system. Sci Rep 2016; 6:19497. [PMID: 26780930 PMCID: PMC4726112 DOI: 10.1038/srep19497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/15/2015] [Indexed: 11/24/2022] Open
Abstract
Hyperentangled Bell-state analysis (HBSA) is an essential method in high-capacity quantum communication and quantum information processing. Here by replacing the two-qubit controlled-phase gate with the two-qubit SWAP gate, we propose a scheme to distinguish the 16 hyperentangled Bell states completely in both the polarization and the spatial-mode degrees of freedom (DOFs) of two-photon systems. The proposed scheme reduces the use of two-qubit interaction which is fragile and cumbersome, and only one auxiliary particle is required. Meanwhile, it reduces the requirement for initializing the auxiliary particle which works as a temporary quantum memory, and does not have to be actively controlled or measured. Moreover, the state of the auxiliary particle remains unchanged after the HBSA operation, and within the coherence time, the auxiliary particle can be repeatedly used in the next HBSA operation. Therefore, the engineering complexity of our HBSA operation is greatly simplified. Finally, we discuss the feasibility of our scheme with current technologies.
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9
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Kwon O, Park KK, Ra YS, Kim YS, Kim YH. Time-bin entangled photon pairs from spontaneous parametric down-conversion pumped by a cw multi-mode diode laser. OPTICS EXPRESS 2013; 21:25492-25500. [PMID: 24150388 DOI: 10.1364/oe.21.025492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Generation of time-bin entangled photon pairs requires the use of the Franson interferometer which consists of two spatially separated unbalanced Mach-Zehnder interferometers through which the signal and idler photons from spontaneous parametric down-conversion (SPDC) are made to transmit individually. There have been two SPDC pumping regimes where the scheme works: the narrowband regime and the double-pulse regime. In the narrowband regime, the SPDC process is pumped by a narrowband cw laser with the coherence length much longer than the path length difference of the Franson interferometer. In the double-pulse regime, the longitudinal separation between the pulse pair is made equal to the path length difference of the Franson interferometer. In this paper, we propose another regime by which the generation of time-bin entanglement is possible and demonstrate the scheme experimentally. In our scheme, differently from the previous approaches, the SPDC process is pumped by a cw multi-mode (i.e., short coherence length) laser and makes use of the coherence revival property of such a laser. The high-visibility two-photon Franson interference demonstrates clearly that high-quality time-bin entanglement source can be developed using inexpensive cw multi-mode diode lasers for various quantum communication applications.
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10
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Zhukovsky SV, Kang D, Abolghasem P, Helt LG, Sipe JE, Helmy AS. Proposal for on-chip generation and control of photon hyperentanglement. OPTICS LETTERS 2011; 36:3548-3550. [PMID: 21931386 DOI: 10.1364/ol.36.003548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An on-chip waveguide-based source of entangled photons capable of switching between generating time-energy entangled and hyperentangled (entangled in both time energy and polarization) photon pairs is proposed. The switching can be done all-optically by rotating the pump polarization. The source is based on multichannel phase matching in Bragg reflection waveguides achieved by engineering the Fresnel reflection of photonic bandgap claddings for differently polarized modes. Analytical results are confirmed in fully vectorial numerical simulations.
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Affiliation(s)
- S V Zhukovsky
- Department of Physics and Institute for Optical Sciences, University of Toronto, Toronto, Ontario, Canada.
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11
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Löffler W, Euser TG, Eliel ER, Scharrer M, Russell PSJ, Woerdman JP. Fiber transport of spatially entangled photons. PHYSICAL REVIEW LETTERS 2011; 106:240505. [PMID: 21770558 DOI: 10.1103/physrevlett.106.240505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 04/20/2011] [Indexed: 05/14/2023]
Abstract
Entanglement in the spatial degrees of freedom of photons is an interesting resource for quantum information. For practical distribution of such entangled photons, it is desirable to use an optical fiber, which in this case has to support multiple transverse modes. Here we report the use of a hollow-core photonic crystal fiber to transport spatially entangled qubits.
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Affiliation(s)
- W Löffler
- Huygens Laboratory, Leiden University, Leiden, The Netherlands.
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12
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Kwon O, Ra YS, Kim YH. Coherence properties of spontaneous parametric down-conversion pumped by a multi-mode cw diode laser. OPTICS EXPRESS 2009; 17:13059-13069. [PMID: 19654710 DOI: 10.1364/oe.17.013059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Coherence properties of the photon pair generated via spontaneous parametric down-conversion pumped by a multi-mode cw diode laser are studied with a Mach-Zehnder interferometer. Each photon of the pair enters a different input port of the interferometer and the biphoton coherence properties are studied with a two-photon detector placed at one output port. When the photon pair simultaneously enters the interferometer, periodic recurrence of the biphoton de Broglie wave packet is observed, closely resembling the coherence properties of the pump diode laser. With non-zero delays between the photons at the input ports, biphoton interference exhibits the same periodic recurrence but the wave packet shapes are shown to be dependent on both the input delay as well as the interferometer delay. These properties could be useful for building engineered entangled photon sources based on diode laser-pumped spontaneous parametric down-conversion.
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Affiliation(s)
- Osung Kwon
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Korea
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13
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Cabello A, Rossi A, Vallone G, De Martini F, Mataloni P. Proposed bell experiment with genuine energy-time entanglement. PHYSICAL REVIEW LETTERS 2009; 102:040401. [PMID: 19257405 DOI: 10.1103/physrevlett.102.040401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Indexed: 05/27/2023]
Abstract
Franson's Bell experiment with energy-time entanglement [Phys. Rev. Lett. 62, 2205 (1989)10.1103/PhysRevLett.62.2205] does not rule out all local hidden variable models. This defect can be exploited to compromise the security of Bell inequality-based quantum cryptography. We introduce a novel Bell experiment using genuine energy-time entanglement, based on a novel interferometer, which rules out all local hidden variable models. The scheme is feasible with actual technology.
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Affiliation(s)
- Adán Cabello
- Departamento de Física Aplicada II, Universidad de Sevilla, E-41012 Sevilla, Spain.
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14
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Jha AK, Malik M, Boyd RW. Exploring energy-time entanglement using geometric phase. PHYSICAL REVIEW LETTERS 2008; 101:180405. [PMID: 18999801 DOI: 10.1103/physrevlett.101.180405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Indexed: 05/27/2023]
Abstract
Using the signal and idler photons produced by parametric down-conversion, we report an experimental observation of a violation of the Bell inequality for energy and time based purely on the geometric phases of the signal and idler photons. We thus show that energy-time entanglement between the signal and idler photons can be explored by means of their geometric phases. These results may have important practical implications for quantum information science by providing an additional means by which entanglement can be manipulated.
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Affiliation(s)
- Anand Kumar Jha
- The Institute of Optics, University of Rochester, Rochester, New York 14627, USA
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15
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Yarnall T, Abouraddy AF, Saleh BEA, Teich MC. Spatial coherence effects on second- and fourth-order temporal interference. OPTICS EXPRESS 2008; 16:7634-7640. [PMID: 18545470 DOI: 10.1364/oe.16.007634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report the results of two experiments performed with two-photon light, produced via collinear degenerate optical spontaneous parametric downconversion (SPDC), in which both second-order (one-photon) and fourth-order (two-photon) interferograms are recorded in a Mach-Zehnder interferometer (MZI). In the first experiment, high-visibility fringes are obtained for both the second- and fourth-order interferograms. In the second experiment, the MZI is modified by the removal of a mirror from one of its arms; this leaves the fourth-order interferogram unchanged, but extinguishes the second-order interferogram. A theoretical model that takes into consideration both the temporal and spatial degrees-of-freedom of the two-photon state successfully explains the results. While the temporal interference in the MZI is independent of the spatial coherence of the source, that of the modified MZI is not.
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Affiliation(s)
- Timothy Yarnall
- Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, Massachusetts 02420-9108, USA
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16
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Barreiro JT, Langford NK, Peters NA, Kwiat PG. Generation of hyperentangled photon pairs. PHYSICAL REVIEW LETTERS 2005; 95:260501. [PMID: 16486324 DOI: 10.1103/physrevlett.95.260501] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Indexed: 05/06/2023]
Abstract
We experimentally demonstrate the first quantum system entangled in every degree of freedom (hyperentangled). Using pairs of photons produced in spontaneous parametric down-conversion, we verify entanglement by observing a Bell-type inequality violation in each degree of freedom: polarization, spatial mode, and time energy. We also produce and characterize maximally hyperentangled states and novel states simultaneously exhibiting both quantum and classical correlations. Finally, we report the tomography of a 2 x 2 x 3 x 3 system (36-dimensional Hilbert space), which we believe is the first reported photonic entangled system of this size to be so characterized.
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Affiliation(s)
- Julio T Barreiro
- Department of Physics, University of Illinois at Urbana-Champaign, 61801-3080, USA
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17
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Reid MD. Incompatibility of macroscopic local realism with quantum mechanics in measurements with macroscopic uncertainties. PHYSICAL REVIEW LETTERS 2000; 84:2765-2769. [PMID: 11018938 DOI: 10.1103/physrevlett.84.2765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/1999] [Indexed: 05/23/2023]
Abstract
We show that quantum mechanics predicts a contradiction with local hidden variable theories for photon number measurements which have limited resolving power, to the point of imposing an uncertainty in the photon number result which is macroscopic in absolute terms. We show how this can be interpreted as a failure of a new premise, macroscopic local realism.
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Affiliation(s)
- MD Reid
- Physics Department, University of Queensland, Brisbane, Australia
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18
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Briand J, Thuriez S, Giardino G, Borsoni G, Froment M, Eddrief M, Sébenne C. Observation of Hollow Atoms or Ions above Insulator and Metal Surfaces. PHYSICAL REVIEW LETTERS 1996; 77:1452-1455. [PMID: 10063082 DOI: 10.1103/physrevlett.77.1452] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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