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

arXiv:2608.09454

An accelerator-based source of high-intensity quantum-entangled annihilation gamma photons

Riad Suleiman

physics.acc-phquant-phSubmitted Aug 10, 2026• Announced Aug 11, 2026• 0 citations
arXivHTMLPDF

Abstract

We present the concept and development of a novel accelerator-based source of high-intensity quantum-entangled 511 keV gamma-ray pairs produced through positron-electron annihilation. The source leverages the unique capabilities of the proposed Jefferson Lab positron facility to generate polarized, high-current positron beams with a well-defined time structure. These beams enable the production of entangled annihilation photons at intensities far exceeding those available from conventional radioactive sources. The resulting gamma-ray pairs can be characterized using Compton polarimetry techniques, providing a powerful platform for precision studies of quantum entanglement. The combination of high intensity, controllable polarization, and precise timing also opens new opportunities in medical imaging, materials science, quantum information science, and spintronics. Compared with traditional radioactive sources, the proposed system offers orders-of-magnitude higher photon flux, tunable beam parameters, and unprecedented control of the annihilation process. We discuss the source design, methods for entanglement characterization, potential applications, and future development directions.

Comments
In proceedings of International Workshop on Low Energy Electron Positron Physics at Jefferson Lab (LEEPP2026), 23--27 March 2026

Related papers

Testing entanglement of annihilation photons

A. Ivashkin, J. N. Abdurashitov, Alexander Baranov +5 more

We present a new experimental study of the quantum entanglement of photon pairs produced in positron-electron annihilation at rest. Each annihilation photon has an energy that is five orders of magnitude higher than the energy of photons in optical experiments. It provides a unique opportunity for controlled Compton pre-scattering of initial photons before the polarization measurements. The experimental setup includes a system of Compton polarimeters to measure the angular correlations of annihilation photons in initial and thus prepared pre-scattered states. For the first time, a direct comparison of the polarization correlations of initial and pre-scattered annihilation photons has been carried out. The angular distributions of scattered in polarimeters photons turned out to be the same for both types of events. Moreover, the correlation function in the Bell's inequality is also the same for both states. We discuss the implications of our results for quantum measurement theory and for the quantum-entangled positron emission tomography.

arXiv:2210.07623•Scientific Reports•May 9, 2023•55 citations

Setup of Compton polarimeters for measuring entangled annihilation photons

J. N. Abdurashitov, А. Г. Баранов, D. S. Borisenko +8 more

Abstract An experimental setup for studying the Compton scattering of annihilation photons in various (entangled and decoherent) quantum states is presented. Two entangled γ-quanta with an energy of 511 keV and mutually orthogonal polarizations are produced by positron-electron annihilation in a thin aluminum plate and are emitted in opposite directions. To measure both photons, the setup provides two equivalent arms of Compton polarimeters. A Compton polarimeter consists of a plastic scintillation scatterer and an array of NaI(Tl) detectors for measuring photons deflected at an angle of 90°. The intermediate scatterer of the GAGG scintillator with SiPM readout is inserted into one of the arms to create a tagged decoherence process prior to the measurement of annihilation photons in polarimeters. The performance of Compton scatterers and NaI(Tl) counters is discussed. The polarization modulation factor and the analyzing power of Compton polarimeters are evaluated from the angular distributions of scattered gammas. The Compton scattering of photons in entangled and decoherent states is compared reliably for the first time.

arXiv:2204.04692•Journal of Instrumentation•Mar 1, 2022•22 citations

Roadmap Towards Quantum Entanglement Positron Emission Tomography (QE-PET)

Paweł Moskal, Shiva Abbaszadeh, Harmanjeet Singh Bilkhu +19 more

Annihilation photons are quantum entangled in their polarization, a property that is not accessible in state-of-the-art clinical Positron Emission Tomography (PET). This roadmap describes the current status of research in the emerging field of quantum entanglement applications involving these photons for medical diagnosis. It outlines the underlying physics phenomena and the development of detector systems that can serve as a foundation for future Quantum Entanglement PET (QE-PET) scanners. These scanners will be capable of utilizing the entanglement between annihilation photons by measuring their Compton scattering on electrons. This roadmap comprises up-to-date experimental results on the study of quantum entanglement and the decoherence of annihilation photons, alongside the current theoretical understanding of these phenomena. The methods and detector technologies described herein are being developed (i) in order to enhance standard PET imaging by suppressing random coincidences in the reconstruction of annihilation site density distributions, (ii) in order to establish the degree of quantum entanglement as a diagnostic biomarker for tissue pathology and oxygenation, and (iii) in order to elaborate a method for pH imaging. Whether entanglement-based imaging and pH mapping can be successfully translated into clinical practice remains an open question and a subject of exciting ongoing research. This roadmap serves as an invitation to the scientific community to join this burgeoning field.

physics.med-phCross-listedarXiv:2607.12182•Jul 15, 2026•0 citations

Experimental observation of polarization correlation of entangled photons from positronium atom using J-PET detector

Deepak Kumar, Sushil Kumar Sharma, Paweł Moskal

Quantum entanglement is one of the fundamental correlations between particles that has not yet been confirmed with high-energy photons. Quantum electrodynamics (QED) predicts that annihilation photons produced by the decay of the singlet state of positronium (Ps) atoms are entangled in their polarization. Since these photons have an energy of 511 keV, there is no polarizer to measure the polarization of these photons. However, the direction of the scattering photons when interacting with an electron via the Compton process depends strongly on the polarization of the photon. Therefore, Compton scattering can be used as a polarization analyser. The polarization direction of the photon can be defined as the cross product of the momentum vector of the incident and scattered photon. By measuring the polarization of annihilation photons originating from Ps decays, their polarization correlation can be determined. Measuring this correlation will for the first time, will answer the open question of studying quantum entanglement in high-energy photons. Moreover, it also have potential applications in PET imaging, where the quality of image reconstruction directly depends on the selection of pure annihilation photons, which can be separated based on the strength of the polarization correlation. In this paper, we report on the method for determining the polarization correlation of annihilation photons using the J-PET detector.

European Physical Society Conference on High Energy Physics (EPS-HEP)•Dec 14, 2023•2 citations

Bell Test of Photons from Electron-Positron Annihilation via POVM-based Compton Polarimetry

Jack Clarke, Preslav Asenov, Jesse Smeets +3 more

Quantum entanglement between gamma-ray photons emitted following electron-positron annihilation is expected to be maximal and may be characterized via non-classical polarization correlations. However, this is difficult to verify experimentally because there are no established schemes that approach ideal projective-polarization measurements for high-energy photons. Hence, polarization entanglement between MeV-scale annihilation photons has not yet been conclusively demonstrated. We develop here a framework that models polarization measurements of high-energy photons via Compton polarimetry, employing the formalism of positive operator-valued measures (POVMs). We extend the POVM description to sequences of repeated interactions and show that the measurement converges toward an ideal projective measurement of linear polarization as the number of interactions increases. We demonstrate that this progressive improvement in measurement sharpness can enable the experimental violation of CHSH inequalities.

quant-pharXiv:2604.25034•Apr 29, 2026•0 citations

Towards quantum technologies with gamma photons

Sorin Ujeniuc, R. Suvaila

Abstract In the context of the second quantum revolution, the ability to manipulate quantum systems is already used for various techniques and a growing number of technology demonstrators, mostly with low energy photons. In this frame, our intention is to extend quantum technologies to gamma photons. Our aim is to take advantage of resources brought by entanglement with higher energy particles, particularly electron-positron annihilation quanta. Tools for low frequency quantum experiments are not suitable for penetrant radiation, consequently we need to use effects typical to the keV-MeV energy range instead. High energy photon protocols would include fundamental properties testing, industrial imaging, quantum random number generators, quantum simulators, military applications and improvement of already existing medical procedures. In this paper we review some important steps in the study of annihilation photon correlations, we point out the experimental differences and necessities with respect to the energy increase in quantum photonic experiments and we describe the design of a quantum gamma device we propose for experiments meant to prove feasibility of gamma ray based protocols. The perspective behind our project is to evidence the possibility to communicate via entangled quanta through media which are not transparent for low energy photons.

EPJ Quantum Technology•Jun 6, 2024•4 citations
We present the concept and development of a novel accelerator-based source of high-intensity quantum-entangled 511 keV gamma-ray pairs produced through positron-electron annihilation. The source leverages the unique capabilities of the proposed Jefferson Lab positron facility to generate polarized, high-current positron beams with a well-defined time structure. These beams enable the production of entangled annihilation photons at intensities far exceeding those available from conventional radioactive sources. The resulting gamma-ray pairs can be characterized using Compton polarimetry techniques, providing a powerful platform for precision studies of quantum entanglement. The combination of high intensity, controllable polarization, and precise timing also opens new opportunities in medical imaging, materials science, quantum information science, and spintronics. Compared with traditional radioactive sources, the proposed system offers orders-of-magnitude higher photon flux, tunable beam parameters, and unprecedented control of the annihilation process. We discuss the source design, methods for entanglement characterization, potential applications, and future development directions.
We present a new experimental study of the quantum entanglement of photon pairs produced in positron-electron annihilation at rest. Each annihilation photon has an energy that is five orders of magnitude higher than the energy of photons in optical experiments. It provides a unique opportunity for controlled Compton pre-scattering of initial photons before the polarization measurements. The experimental setup includes a system of Compton polarimeters to measure the angular correlations of annihilation photons in initial and thus prepared pre-scattered states. For the first time, a direct comparison of the polarization correlations of initial and pre-scattered annihilation photons has been carried out. The angular distributions of scattered in polarimeters photons turned out to be the same for both types of events. Moreover, the correlation function in the Bell's inequality is also the same for both states. We discuss the implications of our results for quantum measurement theory and for the quantum-entangled positron emission tomography.
Abstract An experimental setup for studying the Compton scattering of annihilation photons in various (entangled and decoherent) quantum states is presented. Two entangled γ-quanta with an energy of 511 keV and mutually orthogonal polarizations are produced by positron-electron annihilation in a thin aluminum plate and are emitted in opposite directions. To measure both photons, the setup provides two equivalent arms of Compton polarimeters. A Compton polarimeter consists of a plastic scintillation scatterer and an array of NaI(Tl) detectors for measuring photons deflected at an angle of 90°. The intermediate scatterer of the GAGG scintillator with SiPM readout is inserted into one of the arms to create a tagged decoherence process prior to the measurement of annihilation photons in polarimeters. The performance of Compton scatterers and NaI(Tl) counters is discussed. The polarization modulation factor and the analyzing power of Compton polarimeters are evaluated from the angular distributions of scattered gammas. The Compton scattering of photons in entangled and decoherent states is compared reliably for the first time.
Annihilation photons are quantum entangled in their polarization, a property that is not accessible in state-of-the-art clinical Positron Emission Tomography (PET). This roadmap describes the current status of research in the emerging field of quantum entanglement applications involving these photons for medical diagnosis. It outlines the underlying physics phenomena and the development of detector systems that can serve as a foundation for future Quantum Entanglement PET (QE-PET) scanners. These scanners will be capable of utilizing the entanglement between annihilation photons by measuring their Compton scattering on electrons. This roadmap comprises up-to-date experimental results on the study of quantum entanglement and the decoherence of annihilation photons, alongside the current theoretical understanding of these phenomena. The methods and detector technologies described herein are being developed (i) in order to enhance standard PET imaging by suppressing random coincidences in the reconstruction of annihilation site density distributions, (ii) in order to establish the degree of quantum entanglement as a diagnostic biomarker for tissue pathology and oxygenation, and (iii) in order to elaborate a method for pH imaging. Whether entanglement-based imaging and pH mapping can be successfully translated into clinical practice remains an open question and a subject of exciting ongoing research. This roadmap serves as an invitation to the scientific community to join this burgeoning field.
Quantum entanglement is one of the fundamental correlations between particles that has not yet been confirmed with high-energy photons. Quantum electrodynamics (QED) predicts that annihilation photons produced by the decay of the singlet state of positronium (Ps) atoms are entangled in their polarization. Since these photons have an energy of 511 keV, there is no polarizer to measure the polarization of these photons. However, the direction of the scattering photons when interacting with an electron via the Compton process depends strongly on the polarization of the photon. Therefore, Compton scattering can be used as a polarization analyser. The polarization direction of the photon can be defined as the cross product of the momentum vector of the incident and scattered photon. By measuring the polarization of annihilation photons originating from Ps decays, their polarization correlation can be determined. Measuring this correlation will for the first time, will answer the open question of studying quantum entanglement in high-energy photons. Moreover, it also have potential applications in PET imaging, where the quality of image reconstruction directly depends on the selection of pure annihilation photons, which can be separated based on the strength of the polarization correlation. In this paper, we report on the method for determining the polarization correlation of annihilation photons using the J-PET detector.
Quantum entanglement between gamma-ray photons emitted following electron-positron annihilation is expected to be maximal and may be characterized via non-classical polarization correlations. However, this is difficult to verify experimentally because there are no established schemes that approach ideal projective-polarization measurements for high-energy photons. Hence, polarization entanglement between MeV-scale annihilation photons has not yet been conclusively demonstrated. We develop here a framework that models polarization measurements of high-energy photons via Compton polarimetry, employing the formalism of positive operator-valued measures (POVMs). We extend the POVM description to sequences of repeated interactions and show that the measurement converges toward an ideal projective measurement of linear polarization as the number of interactions increases. We demonstrate that this progressive improvement in measurement sharpness can enable the experimental violation of CHSH inequalities.
Abstract In the context of the second quantum revolution, the ability to manipulate quantum systems is already used for various techniques and a growing number of technology demonstrators, mostly with low energy photons. In this frame, our intention is to extend quantum technologies to gamma photons. Our aim is to take advantage of resources brought by entanglement with higher energy particles, particularly electron-positron annihilation quanta. Tools for low frequency quantum experiments are not suitable for penetrant radiation, consequently we need to use effects typical to the keV-MeV energy range instead. High energy photon protocols would include fundamental properties testing, industrial imaging, quantum random number generators, quantum simulators, military applications and improvement of already existing medical procedures. In this paper we review some important steps in the study of annihilation photon correlations, we point out the experimental differences and necessities with respect to the energy increase in quantum photonic experiments and we describe the design of a quantum gamma device we propose for experiments meant to prove feasibility of gamma ray based protocols. The perspective behind our project is to evidence the possibility to communicate via entangled quanta through media which are not transparent for low energy photons.