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Open accessJournal ArticleDOI: 10.1103/PRXQUANTUM.2.010337

Ultrabright Entangled-Photon-Pair Generation from an Al Ga As -On-Insulator Microring Resonator

04 Mar 2021-Vol. 2, Iss: 1, pp 010337
Abstract: An on-chip entangled-photon pair source from an AlGaAs-on-insulator microring resonator is demonstrated, offering a nearly 1000-fold improvement over state-of-the-art brightness while maintaining g97% fidelity and g99% purity.

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Topics: Resonator (54%)

8 results found

Open accessPosted Content
Xiang Guo1, Chang-Ling Zou1, Carsten Schuck1, Hojoong Jung1  +2 moreInstitutions (1)
Abstract: Quantum photonic chips, which integrate quantum light sources alongside active and passive optical elements, as well as single photon detectors, show great potential for photonic quantum information processing and quantum technology. Mature semiconductor nanofabrication processes allow for scaling such photonic integrated circuits to on-chip networks of increasing complexity. Second order nonlinear materials are the method of choice for generating photonic quantum states in the overwhelming part of linear optic experiments using bulk components but integration with waveguide circuitry on a nanophotonic chip proved to be challenging. Here we demonstrate such an on-chip parametric down-conversion source of photon pairs based on second order nonlinearity in an Aluminum nitride microring resonator. We show the potential of our source for quantum information processing by measuring high-visibility antibunching of heralded single photons with nearly ideal state purity. Our down conversion source operates with high brightness and low noise, yielding pairs of correlated photons at MHz-rates with high coincidence-to-accidental ratio. The generated photon pairs are spectrally far separated from the pump field, providing good potential for realizing sufficient on-chip filtering and monolithic integration of quantum light sources, waveguide circuits and single photon detectors.

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Topics: Spontaneous parametric down-conversion (64%), Quantum technology (63%), Photonics (58%) ... read more

108 Citations

Open accessJournal Article
Abstract: We performed an loophole-free test of Bells inequalities. The probability that local realism is compatible with our results is less than 5.9×10-9.

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42 Citations

Open accessJournal Article
Abstract: Quantum entanglement is among the most fascinating aspects of quantum theory. Entangled optical photons are now widely used for fundamental tests of quantum mechanics and applications such as quantum cryptography. Several recent experiments demonstrated entanglement of optical photons with trapped ions, atoms and atomic ensembles, which are then used to connect remote long-term memory nodes in distributed quantum networks. Here we realize quantum entanglement between the polarization of a single optical photon and a solid-state qubit associated with the single electronic spin of a nitrogen vacancy centre in diamond. Our experimental entanglement verification uses the quantum eraser technique, and demonstrates that a high degree of control over interactions between a solid-state qubit and the quantum light field can be achieved. The reported entanglement source can be used in studies of fundamental quantum phenomena and provides a key building block for the solid-state realization of quantum optical networks.

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Topics: Qubit (71%), Phase qubit (70%), Flux qubit (67%) ... read more

38 Citations

Open accessJournal ArticleDOI: 10.1038/S41534-021-00462-7
Zichang Zhang1, Chenzhi Yuan1, Si Shen1, Hao Yu1  +17 moreInstitutions (5)
Abstract: In this paper, we demonstrate the generation of high-performance entangled photon-pairs in different degrees of freedom from a single piece of fiber pigtailed periodically poled LiNbO3 (PPLN) waveguide. We utilize cascaded second-order nonlinear optical processes, i.e., second-harmonic generation (SHG) and spontaneous parametric downconversion (SPDC), to generate photon-pairs. Previously, the performance of the photon-pairs is contaminated by Raman noise photons. Here by fiber-integrating the PPLN waveguide with noise-rejecting filters, we obtain a coincidence-to-accidental ratio (CAR) higher than 52,600 with photon-pair generation and detection rate of 52.36 kHz and 3.51 kHz, respectively. Energy-time, frequency-bin, and time-bin entanglement is prepared by coherently superposing correlated two-photon states in these degrees of freedom, respectively. The energy-time entangled two-photon states achieve the maximum value of CHSH-Bell inequality of S = 2.71 ± 0.02 with two-photon interference visibility of 95.74 ± 0.86%. The frequency-bin entangled two-photon states achieve fidelity of 97.56 ± 1.79% with a spatial quantum beating visibility of 96.85 ± 2.46%. The time-bin entangled two-photon states achieve the maximum value of CHSH-Bell inequality of S = 2.60 ± 0.04 and quantum tomographic fidelity of 89.07 ± 4.35%. Our results provide a potential candidate for the quantum light source in quantum photonics.

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Topics: Quantum entanglement (57%), Photonics (52%), Photon (51%)

1 Citations


57 results found

Open accessJournal ArticleDOI: 10.1136/BJO.46.11.704

36,037 Citations

Open accessJournal ArticleDOI: 10.1103/PHYSREVLETT.75.4337
Paul G. Kwiat1, Klaus Mattle1, Harald Weinfurter1, Anton Zeilinger1  +2 moreInstitutions (2)
Abstract: We report on a high-intensity source of polarization-entangled photon pairs with high momentum definition. Type-II noncollinear phase matching in parametric down conversion produces true entanglement: No part of the wave function must be discarded, in contrast to previous schemes. With two-photon fringe visibilities in excess of 97%, we demonstrated a violation of Bell's inequality by over 100 standard deviations in less than 5 min. The new source allowed ready preparation of all four of the EPR-Bell states.

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2,429 Citations

Journal ArticleDOI: 10.1103/PHYSREVD.10.526
John F. Clauser1, Michael A. Horne2Institutions (2)
15 Jul 1974-Physical Review D
Abstract: A broad class of theories, called "objective local theories," is defined, motivation for considering these theories is given, and experimental consequences of the class are investigated. An extension of previous analyses by Bell and by Clauser et al. shows that predictions of objective local theories and of quantum mechanics differ, and that an experimental test of the entire family of objective local theories can be performed. The experimental requirements are given. Objective local theories satisfying a plausible but experimentally untestable supplementary assumption are shown to be incompatible with existing experimental data.

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Topics: Superdeterminism (58%), CHSH inequality (57%), Bell test experiments (55%) ... read more

1,240 Citations

Open accessJournal ArticleDOI: 10.1103/PHYSREVLETT.115.250401
Abstract: Local realism is the worldview in which physical properties of objects exist independently of measurement and where physical influences cannot travel faster than the speed of light. Bell's theorem states that this worldview is incompatible with the predictions of quantum mechanics, as is expressed in Bell's inequalities. Previous experiments convincingly supported the quantum predictions. Yet, every experiment requires assumptions that provide loopholes for a local realist explanation. Here, we report a Bell test that closes the most significant of these loopholes simultaneously. Using a well-optimized source of entangled photons, rapid setting generation, and highly efficient superconducting detectors, we observe a violation of a Bell inequality with high statistical significance. The purely statistical probability of our results to occur under local realism does not exceed 3.74×10^{-31}, corresponding to an 11.5 standard deviation effect.

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Topics: Bell test experiments (74%), Local hidden variable theory (73%), Bell state (67%) ... read more

995 Citations

Open accessJournal ArticleDOI: 10.1103/PHYSREVLETT.115.250402
Abstract: We present a loophole-free violation of local realism using entangled photon pairs. We ensure that all relevant events in our Bell test are spacelike separated by placing the parties far enough apart and by using fast random number generators and high-speed polarization measurements. A high-quality polarization-entangled source of photons, combined with high-efficiency, low-noise, single-photon detectors, allows us to make measurements without requiring any fair-sampling assumptions. Using a hypothesis test, we compute p values as small as 5.9×10^{-9} for our Bell violation while maintaining the spacelike separation of our events. We estimate the degree to which a local realistic system could predict our measurement choices. Accounting for this predictability, our smallest adjusted p value is 2.3×10^{-7}. We therefore reject the hypothesis that local realism governs our experiment.

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955 Citations

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