scholarly journals State-independent test of quantum contextuality with either single photons or coherent light

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dengke Qu ◽  
Kunkun Wang ◽  
Lei Xiao ◽  
Xiang Zhan ◽  
Peng Xue
Keyword(s):  
Light Field ◽  
Quantum Information Processing ◽  
Single Photons ◽  
Experimental Demonstration ◽  
Coherent Light ◽  
Important Goal ◽  
Classical Physics ◽  
Independent Test ◽  
Classical Correlations ◽  
Classical Behavior

AbstractContextuality is a phenomenon at the heart of quantum mechanics different from classical behavior and has been recently identified as a resource in quantum information processing. Experimental demonstration of contextuality is thus an important goal. We experimentally demonstrate a test of state-independent contextuality in a four-dimensional Hilbert space with single photons and violate the inequality by at least 387 standard deviations. Despite imperfections and possible measurement disturbance, our results cannot be explained in non-contextual models. We also provide a theoretical analysis of a test of contextuality with a coherent light field and show how the definitions affect the emergence of non-classical correlations. Our result sheds new light on the conflict between quantum and classical physics.

scholarly journals Optical spin-state polarization in a binuclear europium complex towards molecule-based coherent light-spin interfaces

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kuppusamy Senthil Kumar ◽  
Diana Serrano ◽  
Aline M. Nonat ◽  
Benoît Heinrich ◽  
Lydia Karmazin ◽  
...  
Keyword(s):  
Ground State ◽  
Quantum Information Processing ◽  
Optical Transition ◽  
Molecular Engineering ◽  
Coherent Light ◽  
Nuclear Spins ◽  
Rare Earth Ion ◽  
Molecular Systems ◽  
Homogeneous Linewidth ◽  
State Spin

AbstractThe success of the emerging field of solid-state optical quantum information processing (QIP) critically depends on the access to resonant optical materials. Rare-earth ion (REI)-based molecular systems, whose quantum properties could be tuned taking advantage of molecular engineering strategies, are one of the systems actively pursued for the implementation of QIP schemes. Herein, we demonstrate the efficient polarization of ground-state nuclear spins—a fundamental requirement for all-optical spin initialization and addressing—in a binuclear Eu(III) complex, featuring inhomogeneously broadened 5D0 → 7F0 optical transition. At 1.4 K, long-lived spectral holes have been burnt in the transition: homogeneous linewidth (Γh) = 22 ± 1 MHz, which translates as optical coherence lifetime (T2opt) = 14.5 ± 0.7 ns, and ground-state spin population lifetime (T1spin) = 1.6 ± 0.4 s have been obtained. The results presented in this study could be a progressive step towards the realization of molecule-based coherent light-spin QIP interfaces.

scholarly journals Optical Chirality and Single-Photon Isolation

2020 ◽  
Author(s):  
Lei Tang ◽  
Keyu Xia
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Kerr Nonlinearity ◽  
Single Photons ◽  
Optical Isolation ◽  
Optical Chirality ◽  
Magneto Optical Effect ◽  
Quantum Optical

Optical isolation is important for protecting a laser from damage due to the detrimental back reflection of light. It typically relies on breaking Lorentz reciprocity and normally is achieved via the Faraday magneto-optical effect, requiring a strong external magnetic field. Single-photon isolation, the quantum counterpart of optical isolation, is the key functional component in quantum information processing, but its realization is challenging. In this chapter, we present all-optical schemes for isolating the backscattering from single photons. In the first scheme, we show the single-photon isolation can be realized by using a chiral quantum optical system, in which a quantum emitter asymmetrically couples to nanowaveguide modes or whispering-gallery modes with high optical chirality. Secondly, we propose a chiral optical Kerr nonlinearity to bypass the so-called dynamical reciprocity in nonlinear optics and then achieve room-temperature photon isolation with low insertion loss. The concepts we present may pave the way for quantum information processing in an unconventional way.

scholarly journals A versatile source of single photons for quantum information processing

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael Förtsch ◽  
Josef U. Fürst ◽  
Christoffer Wittmann ◽  
Dmitry Strekalov ◽  
Andrea Aiello ◽  
...  
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Single Photons

Recurrent retrieval of the coherent light field phase

1992 ◽  
Vol 4 (1) ◽  
pp. 37-41
Author(s):  
V. V. Kotlyar ◽  
V. A. Soifer ◽  
S. V. Filippov
Keyword(s):  
Light Field ◽  
Coherent Light ◽  
Field Phase

scholarly journals Optical π phase shift created with a single-photon pulse

2016 ◽  
Vol 2 (4) ◽  
pp. e1600036 ◽  
Author(s):  
Daniel Tiarks ◽  
Steffen Schmidt ◽  
Gerhard Rempe ◽  
Stephan Dürr
Keyword(s):  
Phase Shift ◽  
Light Pulse ◽  
Light Field ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Electromagnetically Induced Transparency ◽  
Logic Gate ◽  
Quantum Logic Gate ◽  
Photon Pulse ◽  
Induced Transparency

A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing.

scholarly journals Experimental demonstration of superresolution of partially coherent light sources using parity sorting

2021 ◽  
Author(s):  
Sultan Abdul Wadood ◽  
Kevin Liang ◽  
Yiyu Zhou ◽  
Jing Yang ◽  
Miguel Alonso ◽  
...  
Keyword(s):  
Light Sources ◽  
Experimental Demonstration ◽  
Coherent Light ◽  
Partially Coherent ◽  
Partially Coherent Light

scholarly journals Superior properties in room-temperature colloidal-dot quantum emitters revealed by ultralow-dark-count detections of temporally-purified single photons

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Toshiyuki Ihara ◽  
Shigehito Miki ◽  
Toshiki Yamada ◽  
Takahiro Kaji ◽  
Akira Otomo ◽  
...  
Keyword(s):  
Room Temperature ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Photon Emission ◽  
Light Sources ◽  
Single Photons ◽  
Dark Count ◽  
Photon Detectors ◽  
High Quality ◽  
Quantum Emitters

Abstract The realization of high-quality quantum emitters that can operate at room temperature is important for accelerating the application of quantum technologies, such as quantum communication, quantum information processing, and quantum metrology. In this work, we study the photon-antibunching properties on room-temperature emission from individual colloidal quantum dots (CQDs) using superconducting-nanowire single-photon detectors and temporal filtering of the photoluminescence decay curve. We find that high single-photon purities and high photon-generation rates can be simultaneously achieved by removing the signals originating from the sequential two-photon emission of biexcitons created by multiple excitation pulses. We successfully demonstrate that the ultrahigh performance of the room-temperature single-photon sources showing g(2)(0) ≪ 10−2 can be confirmed by the ultralow-dark-count detection of the temporally purified single photons. These findings provide strong evidence for the attractiveness of CQDs as candidates for high-quality room-temperature quantum light sources.

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