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

Physical Review A

Measurement of the two-time intensity-correlation function of arbitrary states

Katarina Stensson, Gunnar G. Bjork

Published Sep 10, 2018• 3 citations
Publisher

Abstract

For light-intensity-correlation measurements, different methods are used in the high-photon-number or high-intensity regime and in the single- and two-photon regime. Hence, there is an unfortunate measurement “gap” primarily for multiphoton, quantum states. These states, for example, multiphoton Fock states, will be increasingly important in the realization of quantum technologies and in exploring the boundaries between quantum and classical optics. We show that a naïve approach based on attenuation, state splitting, and two-detector correlation can give the correct two-time intensity correlation for any state. We analyze how added losses decrease the measurement systematic error. The price to be paid is that the losses increase the measurement statistical error or, alternatively, increase the acquisition time for a given tolerable level of statistical error. We have experimentally demonstrated the feasibility of the method for a coherent state and a quasithermal state. The method is easy to implement in any laboratory and will simplify characterization of medium and highly excited nonclassical states as they become experimentally available.Received 16 March 2018DOI:https://doi.org/10.1103/PhysRevA.98.033812©2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPhoton statisticsQuantum opticsTechniquesPhoton countingAtomic, Molecular & Optical

DOI
10.1103/physreva.98.033812

Related papers

Generation and detection of non-classical photon states

Katarina Stensson

This thesis intends to familiarize the reader with the concepts of photon statistics and correlations in quantum optics. Developing light sources that emit quantum states is central for the realization of quantum technologies. One important step in characterizing these sources is the measurement of field fluctuations and correlations, by coincidence measurements. The expectation value of a coincidence measurement, a simultaneous measurement of two intensities (or, more general, four fields), is represented by the fourth-order correlation function. The value of the correlation function, at zero delay between the detection of two photons, reveals important properties of the state to which they belonged, for example the fluctuations of the photon number. Since predictability is important for many applications, light sources emitting single photons are also characterized by the indistinguishability of consecutively emitted photons, or of two photons from separate emitters. In paper I we investigate blinking behaviour in quantum emitters, and its effect on the interference pattern and photon statistics with photons from two separate emitters. Blinking refers to an emitters transition into a non-emitting state, and subsequent transition back to an emitting state. We show that blinking can not be treated as linear loss, when measuring the fourth-order correlation function for two emitters in a Hong-Ou-Mandel setup. In general, a measurement of the fourth-order correlation function is robust to loss, which makes it a very practical tool. However, the relation between recorded coincidence counts and the correlation function is only direct in the limit of zero detection efficiency, and depends on the detection system. In paper II, we show that by adding a variable attenuation in the beam path, we can trace back to the ''true'' value of the correlation function at zero quantum efficiency. This method improves accuracy in correlation measurements by decreasing a systematic error at the expense of an increased statistical error, which is easier to handle, extending the use of coincidence methods to classical and non-classical multi-photon states.

•Jan 1, 2018•0 citations

Statistical Benchmarking of Scalable Photonic Quantum Systems

Johannes Tiedau, Melanie Engelkemeier, Benjamin Brecht +2 more

Targeting at the realization of scalable photonic quantum technologies, the generation of many photons, their propagation in large optical networks, and a subsequent detection and analysis of sophisticated quantum correlations are essential for the understanding of macroscopic quantum systems. In this experimental contribution, we explore the joint operation of all mentioned ingredients. We benchmark our time-multiplexing framework that includes a high-performance source of multiphoton states and a large multiplexing network, together with unique detectors with high photon-number resolution, readily available for distributing quantum light and measuring complex quantum correlations. Using an adaptive approach that employs flexible time bins, rather than static ones, we successfully verify high-order nonclassical correlations of many photons distributed over many modes. By exploiting the symmetry of our system and using powerful analysis tools, we can analyze correlations that would be inaccessible by classical means otherwise. In particular, we produce on the order of ten photons and distribute them over 64 modes. Nonclassicality is verified with correlation functions up to the 128th order and statistical significances of up to 20 standard deviations.

arXiv:2008.11542•Physical Review Letters•Jan 12, 2021•11 citations

Publisher's Note: Quantum versus classical dynamics in the optical centrifuge [Phys. Rev. A 96 , 033411 (2017)]

Tsafrir Armon, L. Frièdland

Received 12 February 2018DOI:https://doi.org/10.1103/PhysRevA.97.029903©2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAtomic & molecular processes in external fieldsCoherent controlAtomic, Molecular & Optical

Physical Review A•Feb 16, 2018•0 citations

Publisher's Note: Operational quasiprobabilities for continuous variables [Phys. Rev. A 96 , 042121 (2017)]

Jeongwoo Jae, Junghee Ryu, Jinhyoung Lee

Received 15 March 2018DOI:https://doi.org/10.1103/PhysRevA.97.039905©2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum foundationsQuantum information processing with continuous variablesQuantum states of lightQuantum InformationGeneral Physics

Physical Review A•Mar 21, 2018•0 citations

Measuring the time–frequency properties of photon pairs: A short review

Ilaria Gianani, Marco Sbroscia, Marco Barbieri

Encoding information in the time–frequency domain demonstrates its potential for quantum information processing. It offers a novel scheme for communications with large alphabets, computing with large quantum systems, and new approaches to metrology. It is then crucial to secure full control on the generation of time–frequency quantum states and their properties. Here, the authors present an overview of the theoretical background and the technical aspects related to the characterization of time–frequency properties of two-photon states. The authors provide a detailed account of the methodologies that have been implemented for measuring frequency correlations and for the retrieval of the full spectral wavefunction. This effort has benefited enormously from the adaptation of classical metrology schemes to the needs of operating at the single-photon level.

arXiv:1911.12460•AVS Quantum Science•Feb 1, 2020•20 citations

Efficient tomography of coherent optical detectors

Xinyu Chen, Feixiang Xu, Huichao Xu +1 more

We propose an efficient tomography method to address the reconstruction complexity of any general quantum coherent-optical detectors. By extracting the linear loss from the entire detection system, we obtain the effective positive-operator-valued measure in matrix representations with a much smaller size. We apply this method to reconstruct a typical coherent detector: the weak-field homodyne detector. The method also highlights the effects of linear loss on nonclassical features of coherent optical detectors.Received 14 August 2022Accepted 16 November 2022DOI:https://doi.org/10.1103/PhysRevA.106.L051702©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum tomographyQuantum Information

Physical Review A•Nov 30, 2022•1 citation
For light-intensity-correlation measurements, different methods are used in the high-photon-number or high-intensity regime and in the single- and two-photon regime. Hence, there is an unfortunate measurement “gap” primarily for multiphoton, quantum states. These states, for example, multiphoton Fock states, will be increasingly important in the realization of quantum technologies and in exploring the boundaries between quantum and classical optics. We show that a naïve approach based on attenuation, state splitting, and two-detector correlation can give the correct two-time intensity correlation for any state. We analyze how added losses decrease the measurement systematic error. The price to be paid is that the losses increase the measurement statistical error or, alternatively, increase the acquisition time for a given tolerable level of statistical error. We have experimentally demonstrated the feasibility of the method for a coherent state and a quasithermal state. The method is easy to implement in any laboratory and will simplify characterization of medium and highly excited nonclassical states as they become experimentally available.Received 16 March 2018DOI:https://doi.org/10.1103/PhysRevA.98.033812©2018 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPhoton statisticsQuantum opticsTechniquesPhoton countingAtomic, Molecular & Optical
This thesis intends to familiarize the reader with the concepts of photon statistics and correlations in quantum optics. Developing light sources that emit quantum states is central for the realization of quantum technologies. One important step in characterizing these sources is the measurement of field fluctuations and correlations, by coincidence measurements. The expectation value of a coincidence measurement, a simultaneous measurement of two intensities (or, more general, four fields), is represented by the fourth-order correlation function. The value of the correlation function, at zero delay between the detection of two photons, reveals important properties of the state to which they belonged, for example the fluctuations of the photon number. Since predictability is important for many applications, light sources emitting single photons are also characterized by the indistinguishability of consecutively emitted photons, or of two photons from separate emitters. In paper I we investigate blinking behaviour in quantum emitters, and its effect on the interference pattern and photon statistics with photons from two separate emitters. Blinking refers to an emitters transition into a non-emitting state, and subsequent transition back to an emitting state. We show that blinking can not be treated as linear loss, when measuring the fourth-order correlation function for two emitters in a Hong-Ou-Mandel setup. In general, a measurement of the fourth-order correlation function is robust to loss, which makes it a very practical tool. However, the relation between recorded coincidence counts and the correlation function is only direct in the limit of zero detection efficiency, and depends on the detection system. In paper II, we show that by adding a variable attenuation in the beam path, we can trace back to the ''true'' value of the correlation function at zero quantum efficiency. This method improves accuracy in correlation measurements by decreasing a systematic error at the expense of an increased statistical error, which is easier to handle, extending the use of coincidence methods to classical and non-classical multi-photon states.
Targeting at the realization of scalable photonic quantum technologies, the generation of many photons, their propagation in large optical networks, and a subsequent detection and analysis of sophisticated quantum correlations are essential for the understanding of macroscopic quantum systems. In this experimental contribution, we explore the joint operation of all mentioned ingredients. We benchmark our time-multiplexing framework that includes a high-performance source of multiphoton states and a large multiplexing network, together with unique detectors with high photon-number resolution, readily available for distributing quantum light and measuring complex quantum correlations. Using an adaptive approach that employs flexible time bins, rather than static ones, we successfully verify high-order nonclassical correlations of many photons distributed over many modes. By exploiting the symmetry of our system and using powerful analysis tools, we can analyze correlations that would be inaccessible by classical means otherwise. In particular, we produce on the order of ten photons and distribute them over 64 modes. Nonclassicality is verified with correlation functions up to the 128th order and statistical significances of up to 20 standard deviations.
Encoding information in the time–frequency domain demonstrates its potential for quantum information processing. It offers a novel scheme for communications with large alphabets, computing with large quantum systems, and new approaches to metrology. It is then crucial to secure full control on the generation of time–frequency quantum states and their properties. Here, the authors present an overview of the theoretical background and the technical aspects related to the characterization of time–frequency properties of two-photon states. The authors provide a detailed account of the methodologies that have been implemented for measuring frequency correlations and for the retrieval of the full spectral wavefunction. This effort has benefited enormously from the adaptation of classical metrology schemes to the needs of operating at the single-photon level.
We propose an efficient tomography method to address the reconstruction complexity of any general quantum coherent-optical detectors. By extracting the linear loss from the entire detection system, we obtain the effective positive-operator-valued measure in matrix representations with a much smaller size. We apply this method to reconstruct a typical coherent detector: the weak-field homodyne detector. The method also highlights the effects of linear loss on nonclassical features of coherent optical detectors.Received 14 August 2022Accepted 16 November 2022DOI:https://doi.org/10.1103/PhysRevA.106.L051702©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum tomographyQuantum Information