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Hloušek J, Ježek M, Fiurášek J. Direct Experimental Certification of Quantum Non-Gaussian Character and Wigner Function Negativity of Single-Photon Detectors. PHYSICAL REVIEW LETTERS 2021; 126:043601. [PMID: 33576686 DOI: 10.1103/physrevlett.126.043601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Highly nonclassical character of optical quantum detectors, such as single-photon detectors, is essential for preparation of quantum states of light and a vast majority of applications in quantum metrology and quantum information processing. Therefore, it is both fundamentally interesting and practically relevant to investigate the nonclassical features of optical quantum measurements. Here we propose and experimentally demonstrate a procedure for direct certification of quantum non-Gaussianity and Wigner function negativity, two crucial nonclassicality levels, of photonic quantum detectors. Remarkably, we characterize the highly nonclassical properties of the detector by probing it with only two classical thermal states and a vacuum state. We experimentally demonstrate the quantum non-Gaussianity of a single-photon avalanche diode even under the presence of background noise, and we also certify the negativity of the Wigner function of this detector. Our results open the way for direct benchmarking of photonic quantum detectors with a few measurements on classical states.
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Affiliation(s)
- Josef Hloušek
- Department of Optics, Palacký University, 17. listopadu 1192/12, 77146 Olomouc, Czech Republic
| | - Miroslav Ježek
- Department of Optics, Palacký University, 17. listopadu 1192/12, 77146 Olomouc, Czech Republic
| | - Jaromír Fiurášek
- Department of Optics, Palacký University, 17. listopadu 1192/12, 77146 Olomouc, Czech Republic
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2
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Schapeler T, Philipp Höpker J, Bartley TJ. Quantum detector tomography of a 2×2 multi-pixel array of superconducting nanowire single photon detectors. OPTICS EXPRESS 2020; 28:33035-33043. [PMID: 33114973 DOI: 10.1364/oe.404285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/18/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate quantum detector tomography of a commercial 2×2 array of superconducting nanowire single photon detectors. We show that detector-specific figures of merit including efficiency, dark-count and cross-talk probabilities can be directly extracted, without recourse to the underlying detector physics. These figures of merit are directly identified from just four elements of the reconstructed positive operator valued measure (POVM) of the device. We show that the values for efficiency and dark-count probability extracted by detector tomography show excellent agreement with independent measurements of these quantities, and we provide an intuitive operational definition for cross-talk probability. Finally, we show that parameters required for the reconstruction must be carefully chosen to avoid oversmoothing the data.
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Zhang A, Xie J, Xu H, Zheng K, Zhang H, Poon YT, Vedral V, Zhang L. Experimental Self-Characterization of Quantum Measurements. PHYSICAL REVIEW LETTERS 2020; 124:040402. [PMID: 32058739 DOI: 10.1103/physrevlett.124.040402] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Indexed: 06/10/2023]
Abstract
The accurate and reliable description of measurement devices is a central problem in both observing uniquely nonclassical behaviors and realizing quantum technologies from powerful computing to precision metrology. To date quantum tomography is the prevalent tool to characterize quantum detectors. However, such a characterization relies on accurately characterized probe states, rendering reliability of the characterization lost in circular argument. Here we report a self-characterization method of quantum measurements based on reconstructing the response range-the entirety of attainable measurement outcomes, eliminating the reliance on known states. We characterize two representative measurements implemented with photonic setups and obtain fidelities above 99.99% with the conventional tomographic reconstructions. This initiates range-based techniques in characterizing quantum systems and foreshadows novel device-independent protocols of quantum information applications.
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Affiliation(s)
- Aonan Zhang
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation (Ministry of Education), College of Engineering and Applied Sciences and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jie Xie
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation (Ministry of Education), College of Engineering and Applied Sciences and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Huichao Xu
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation (Ministry of Education), College of Engineering and Applied Sciences and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Kaimin Zheng
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation (Ministry of Education), College of Engineering and Applied Sciences and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Han Zhang
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation (Ministry of Education), College of Engineering and Applied Sciences and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yiu-Tung Poon
- Department of Mathematics, Iowa State University, Ames, Iowa 50011, USA
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Center for Quantum Computing, Peng Cheng Laboratory, Shenzhen, 518055, China
| | - Vlatko Vedral
- Atomic and Laser Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX13PU, United Kingdom
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543, Singapore
| | - Lijian Zhang
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation (Ministry of Education), College of Engineering and Applied Sciences and School of Physics, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Hloušek J, Dudka M, Straka I, Ježek M. Accurate Detection of Arbitrary Photon Statistics. PHYSICAL REVIEW LETTERS 2019; 123:153604. [PMID: 31702281 DOI: 10.1103/physrevlett.123.153604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Indexed: 06/10/2023]
Abstract
We report a measurement workflow free of systematic errors consisting of a reconfigurable photon-number-resolving detector, custom electronic circuitry, and faithful data-processing algorithm. We achieve an unprecedented accurate measurement of various photon-number distributions going beyond the number of detection channels with an average fidelity of 0.998, where the error is primarily caused by the sources themselves. Mean numbers of photons cover values up to 20 and faithful autocorrelation measurements range from g^{(2)}=6×10^{-3} to 2. We successfully detect chaotic, classical, nonclassical, non-Gaussian, and negative-Wigner-function light. Our results open new paths for optical technologies by providing full access to the photon-number information without the necessity of detector tomography.
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Affiliation(s)
- Josef Hloušek
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czechia
| | - Michal Dudka
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czechia
| | - Ivo Straka
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czechia
| | - Miroslav Ježek
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czechia
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Theurer T, Egloff D, Zhang L, Plenio MB. Quantifying Operations with an Application to Coherence. PHYSICAL REVIEW LETTERS 2019; 122:190405. [PMID: 31144929 DOI: 10.1103/physrevlett.122.190405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Indexed: 06/09/2023]
Abstract
To describe certain facets of nonclassicality, it is necessary to quantify properties of operations instead of states. This is the case if one wants to quantify how well an operation detects nonclassicality, which is a necessary prerequisite for its use in quantum technologies. To do so rigorously, we build resource theories on the level of operations, exploiting the concept of resource destroying maps. We discuss the two basic ingredients of these resource theories, the free operations and the free superoperations, which are sequential and parallel concatenations with free operations. This leads to defining properties of functionals that are well suited to quantify the resources of operations. We introduce these concepts at the example of coherence. In particular, we present two measures quantifying the ability of an operation to detect, i.e., to use, coherence, one of them with an operational interpretation, and provide methods to evaluate them.
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Affiliation(s)
- Thomas Theurer
- Institute of Theoretical Physics and IQST, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - Dario Egloff
- Institute of Theoretical Physics and IQST, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
- Technical University Dresden, Institute of Theoretical Physics, D-01062 Dresden, Germany
| | - Lijian Zhang
- National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Martin B Plenio
- Institute of Theoretical Physics and IQST, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
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Sperling J, Eckstein A, Clements WR, Moore M, Renema JJ, Kolthammer WS, Nam SW, Lita A, Gerrits T, Walmsley IA, Agarwal GS, Vogel W. Identification of nonclassical properties of light with multiplexing layouts. PHYSICAL REVIEW. A 2017; 96:013804. [PMID: 29670949 PMCID: PMC5901769 DOI: 10.1103/physreva.96.013804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In Sperling et al. [Phys. Rev. Lett. 118, 163602 (2017)], we introduced and applied a detector-independent method to uncover nonclassicality. Here, we extend those techniques and give more details on the performed analysis. We derive a general theory of the positive-operator-valued measure that describes multiplexing layouts with arbitrary detectors. From the resulting quantum version of a multinomial statistics, we infer nonclassicality probes based on a matrix of normally ordered moments. We discuss these criteria and apply the theory to our data which are measured with superconducting transition-edge sensors. Our experiment produces heralded multiphoton states from a parametric down-conversion light source. We show that the known notions of sub-Poisson and sub-binomial light can be deduced from our general approach, and we establish the concept of sub-multinomial light, which is shown to outperform the former two concepts of nonclassicality for our data.
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Affiliation(s)
- J. Sperling
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - A. Eckstein
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - W. R. Clements
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - M. Moore
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - J. J. Renema
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - W. S. Kolthammer
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - S. W. Nam
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - A. Lita
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - T. Gerrits
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - I. A. Walmsley
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, England, United Kingdom
| | - G. S. Agarwal
- Texas A&M University, College Station, Texas 77845, USA
| | - W. Vogel
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23, D-18059 Rostock, Germany
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Sperling J, Clements WR, Eckstein A, Moore M, Renema JJ, Kolthammer WS, Nam SW, Lita A, Gerrits T, Vogel W, Agarwal GS, Walmsley IA. Detector-Independent Verification of Quantum Light. PHYSICAL REVIEW LETTERS 2017; 118:163602. [PMID: 28474918 PMCID: PMC5894853 DOI: 10.1103/physrevlett.118.163602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Indexed: 06/07/2023]
Abstract
We introduce a method for the verification of nonclassical light which is independent of the complex interaction between the generated light and the material of the detectors. This is accomplished by means of a multiplexing arrangement. Its theoretical description yields that the coincidence statistics of this measurement layout is a mixture of multinomial distributions for any classical light field and any type of detector. This allows us to formulate bounds on the statistical properties of classical states. We apply our directly accessible method to heralded multiphoton states which are detected with a single multiplexing step only and two detectors, which are in our work superconducting transition-edge sensors. The nonclassicality of the generated light is verified and characterized through the violation of the classical bounds without the need for characterizing the used detectors.
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Affiliation(s)
- J Sperling
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - W R Clements
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - A Eckstein
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - M Moore
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - J J Renema
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - W S Kolthammer
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - S W Nam
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - A Lita
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - T Gerrits
- National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA
| | - W Vogel
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23, D-18059 Rostock, Germany
| | - G S Agarwal
- Texas A&M University, College Station, Texas 77845, USA
| | - I A Walmsley
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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8
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Harder G, Silberhorn C, Rehacek J, Hradil Z, Motka L, Stoklasa B, Sánchez-Soto LL. Local Sampling of the Wigner Function at Telecom Wavelength with Loss-Tolerant Detection of Photon Statistics. PHYSICAL REVIEW LETTERS 2016; 116:133601. [PMID: 27081977 DOI: 10.1103/physrevlett.116.133601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Indexed: 06/05/2023]
Abstract
We report the experimental point-by-point sampling of the Wigner function for nonclassical states created in an ultrafast pulsed type-II parametric down-conversion source. We use a loss-tolerant time-multiplexed detector based on a fiber-optical setup and a pair of photon-number-resolving avalanche photodiodes. By capitalizing on an expedient data-pattern tomography, we assess the properties of the light states with outstanding accuracy. The method allows us to reliably infer the squeezing of genuine two-mode states without any phase reference.
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Affiliation(s)
- G Harder
- Department of Physics, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
| | - Ch Silberhorn
- Department of Physics, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
- Max-Planck-Institut für die Physik des Lichts, Günther-Scharowsky-Straße 1, Bau 24, 91058 Erlangen, Germany
| | - J Rehacek
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Z Hradil
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - L Motka
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - B Stoklasa
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - L L Sánchez-Soto
- Max-Planck-Institut für die Physik des Lichts, Günther-Scharowsky-Straße 1, Bau 24, 91058 Erlangen, Germany
- Departamento de Óptica, Facultad de Física, Universidad Complutense, 28040 Madrid, Spain
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Altorio M, Genoni MG, Somma F, Barbieri M. Metrology with Unknown Detectors. PHYSICAL REVIEW LETTERS 2016; 116:100802. [PMID: 27015467 DOI: 10.1103/physrevlett.116.100802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Indexed: 06/05/2023]
Abstract
The best possible precision is one of the key figures in metrology, but this is established by the exact response of the detection apparatus, which is often unknown. There exist techniques for detector characterization that have been introduced in the context of quantum technologies but apply as well for ordinary classical coherence; these techniques, though, rely on intense data processing. Here, we show that one can make use of the simpler approach of data fitting patterns in order to obtain an estimate of the Cramér-Rao bound allowed by an unknown detector, and we present applications in polarimetry. Further, we show how this formalism provides a useful calculation tool in an estimation problem involving a continuous-variable quantum state, i.e., a quantum harmonic oscillator.
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Affiliation(s)
- Matteo Altorio
- Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Rome, Italy
| | - Marco G Genoni
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Fabrizia Somma
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Rome, Italy
| | - Marco Barbieri
- Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Rome, Italy
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