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

Science

A junction for single-photon detection

Ian S. Osborne

Published Apr 22, 2021• 0 citations
Publisher

Abstract

Quantum Devices Josephson junctions are simple superconducting devices comprising an insulator or semiconductor separating two superconducting regions. They form the workhorse of superconducting technologies and are exquisitely sensitive to magnetic field. One long-sought proposal has been to use these devices to detect light. Walsh et al. have realized a photosensitive Josephson junction based on graphene that is capable of sensing single infrared photons. Such a photosensitive Josephson junction is expected to operate as a high-speed, low-power consumption optical interconnect for communication between superconducting-based supercomputers and quantum computers. Science , this issue p. [409][1] [1]: /lookup/doi/10.1126/science.abf5539

DOI
10.1126/science.372.6540.356-c

Related papers

Josephson junction infrared single-photon detector

Evan D. Walsh, Woochan Jung, Gil‐Ho Lee +9 more

A junction for single-photon detection Josephson junctions are simple superconducting devices comprising an insulator or semiconductor separating two superconducting regions. They form the workhorse of superconducting technologies and are exquisitely sensitive to magnetic field. One long-sought proposal has been to use these devices to detect light. Walsh et al. have realized a photosensitive Josephson junction based on graphene that is capable of sensing single infrared photons. Such a photosensitive Josephson junction is expected to operate as a high-speed, low-power consumption optical interconnect for communication between superconducting-based supercomputers and quantum computers. Science , this issue p. 409

•Jan 1, 2021•68 citations

Josephson junction infrared single-photon detector

Evan D. Walsh, Woochan Jung, Gil-Ho Lee +9 more

Josephson junctions are superconducting devices used as high-sensitivity magnetometers and voltage amplifiers as well as the basis of high-performance cryogenic computers and superconducting quantum computers. Although device performance can be degraded by the generation of quasiparticles formed from broken Cooper pairs, this phenomenon also opens opportunities to sensitively detect electromagnetic radiation. We demonstrate single near-infrared photon detection by coupling photons to the localized surface plasmons of a graphene-based Josephson junction. Using the photon-induced switching statistics of the current-biased device, we reveal the critical role of quasiparticles generated by the absorbed photon in the detection mechanism. The photon sensitivity will enable a high-speed, low-power optical interconnect for future superconducting computing architectures.

arXiv:2011.02624•Science•Apr 22, 2021•98 citations

Detecting Single Photons with Graphene-Based Josephson Junctions

Evan D. Walsh

In this work I present theory, modeling, and experimentation demonstrating that the graphene-based Josephson junction (GJJ) is a capable system for the detection of single photons across the electromagnetic spectrum, from the microwave to the infrared. Two different detection mechanisms are exposed: 1) heating of the graphene weak link in the GJJ and 2) quasiparticle generation in the GJJ superconducting contacts. The first relies on graphene's exceptionally low heat capacity and its decoupled electron and phonon systems. I show in modeling that these thermal properties can lead to a GJJ photon detector for very low energy microwave photons. Experimentally, I show that a GJJ bolometer with its graphene weak link coupled to a microwave resonator can achieve an energy resolution equivalent to a single 32-GHz photon. The second detection mechanism reveals itself in the illumination of a GJJ with near-infrared light. I experimentally demonstrate single-photon detection in this system and show that the data is well fit by a model where photon-induced quasiparticles in the superconducting contacts cause the GJJ phase particle to escape. I give an overview of the single-photon, graphene, and Josephson-junction physics required to arrive at these results before presenting the experimental evidence for single-microwave-photon sensitivity and single-infrared-photon detection with the GJJ.

•Nov 23, 2020•0 citations

Graphene-Based Josephson-Junction Single-Photon Detector

Gil‐Ho Lee, Jesse Crossno, Thomas Ohki +6 more

We propose to use graphene-based Josephson junctions (GJJs) to detect single photons in a wide electromagnetic spectrum from visible to radio frequencies. Our approach takes advantage of the exceptionally low electronic heat capacity of monolayer graphene and its constricted thermal conductance to its phonon degrees of freedom. Such a system could provide high-sensitivity photon detection required for research areas including quantum information processing and radio astronomy. As an example, we present our device concepts for GJJ single-photon detectors in both the microwave and infrared regimes. The dark count rate and intrinsic quantum efficiency are computed based on parameters from a measured GJJ, demonstrating feasibility within existing technologies.

Physical Review Letters•Aug 1, 2017•0 citations

Graphene-Based Josephson-Junction Single-Photon Detector

Evan D. Walsh, Dmitri K. Efetov, Gil‐Ho Lee +6 more

Detecting single photons is essential for numerous technologies, from quantum computing to observations of the faintest objects in the universe. The authors propose a detector based on graphene's dual abilities to absorb light across a huge range of wavelengths, and to experience an extreme rise in electronic temperature by absorbing just one photon. Simulations show that these properties allow for high detection efficiency, when the graphene is coupled to superconductors in a Josephson junction at cryogenic temperatures.

arXiv:1703.09736•Physical Review Applied•Aug 24, 2017•99 citations

Superconducting quantum interference devices with graphene junctions.

Michael D. Thompson, Jonathan R. Prance, R. P. Haley +7 more

We present measurements of DC superconducting quantum interference devices based on Nb/graphene/Nb Josephson junctions. The superconducting proximity effect in graphene can be used to build Josephson junctions whose critical current can be controlled by field-effect gates. These junctions combine the tunability of semiconductor Josephson junctions with the high critical currents and low contact resistances of metal SNS junctions. By using local gates, the SQUID junction critical currents can be modified individually and this allows the sensitivity and symmetry of the SQUID to be controlled in-situ. We compare the critical current of the SQUID with simulations that include a non-sinusoidal current phase relation in the junctions, as expected for ballistic graphene junctions. We also investigate the transfer function of the device in both symmetric and asymmetric configurations and find a highest transfer function of 300 μV/Φ0. Graphene Josephson junctions have the potential to add functionality to existing technologies; for example, to make SQUID magnetometers with tunable sensitivity or superconducting qubits with fast electrical control.

Bulletin of the American Physical Society•Mar 17, 2017•0 citations
Quantum Devices
Josephson junctions are simple superconducting devices comprising an insulator or semiconductor separating two superconducting regions. They form the workhorse of superconducting technologies and are exquisitely sensitive to magnetic field. One long-sought proposal has been to use these devices to detect light. Walsh et al. have realized a photosensitive Josephson junction based on graphene that is capable of sensing single infrared photons. Such a photosensitive Josephson junction is expected to operate as a high-speed, low-power consumption optical interconnect for communication between superconducting-based supercomputers and quantum computers.
Science , this issue p. 409
A junction for single-photon detection Josephson junctions are simple superconducting devices comprising an insulator or semiconductor separating two superconducting regions. They form the workhorse of superconducting technologies and are exquisitely sensitive to magnetic field. One long-sought proposal has been to use these devices to detect light. Walsh et al. have realized a photosensitive Josephson junction based on graphene that is capable of sensing single infrared photons. Such a photosensitive Josephson junction is expected to operate as a high-speed, low-power consumption optical interconnect for communication between superconducting-based supercomputers and quantum computers. Science , this issue p. 409
Josephson junctions are superconducting devices used as high-sensitivity magnetometers and voltage amplifiers as well as the basis of high-performance cryogenic computers and superconducting quantum computers. Although device performance can be degraded by the generation of quasiparticles formed from broken Cooper pairs, this phenomenon also opens opportunities to sensitively detect electromagnetic radiation. We demonstrate single near-infrared photon detection by coupling photons to the localized surface plasmons of a graphene-based Josephson junction. Using the photon-induced switching statistics of the current-biased device, we reveal the critical role of quasiparticles generated by the absorbed photon in the detection mechanism. The photon sensitivity will enable a high-speed, low-power optical interconnect for future superconducting computing architectures.
In this work I present theory, modeling, and experimentation demonstrating that the graphene-based Josephson junction (GJJ) is a capable system for the detection of single photons across the electromagnetic spectrum, from the microwave to the infrared. Two different detection mechanisms are exposed: 1) heating of the graphene weak link in the GJJ and 2) quasiparticle generation in the GJJ superconducting contacts. The first relies on graphene's exceptionally low heat capacity and its decoupled electron and phonon systems. I show in modeling that these thermal properties can lead to a GJJ photon detector for very low energy microwave photons. Experimentally, I show that a GJJ bolometer with its graphene weak link coupled to a microwave resonator can achieve an energy resolution equivalent to a single 32-GHz photon. The second detection mechanism reveals itself in the illumination of a GJJ with near-infrared light. I experimentally demonstrate single-photon detection in this system and show that the data is well fit by a model where photon-induced quasiparticles in the superconducting contacts cause the GJJ phase particle to escape. I give an overview of the single-photon, graphene, and Josephson-junction physics required to arrive at these results before presenting the experimental evidence for single-microwave-photon sensitivity and single-infrared-photon detection with the GJJ.
We propose to use graphene-based Josephson junctions (GJJs) to detect single photons in a wide electromagnetic spectrum from visible to radio frequencies. Our approach takes advantage of the exceptionally low electronic heat capacity of monolayer graphene and its constricted thermal conductance to its phonon degrees of freedom. Such a system could provide high-sensitivity photon detection required for research areas including quantum information processing and radio astronomy. As an example, we present our device concepts for GJJ single-photon detectors in both the microwave and infrared regimes. The dark count rate and intrinsic quantum efficiency are computed based on parameters from a measured GJJ, demonstrating feasibility within existing technologies.
Detecting single photons is essential for numerous technologies, from quantum computing to observations of the faintest objects in the universe. The authors propose a detector based on graphene's dual abilities to absorb light across a huge range of wavelengths, and to experience an extreme rise in electronic temperature by absorbing just one photon. Simulations show that these properties allow for high detection efficiency, when the graphene is coupled to superconductors in a Josephson junction at cryogenic temperatures.
We present measurements of DC superconducting quantum interference devices based on Nb/graphene/Nb Josephson junctions. The superconducting proximity effect in graphene can be used to build Josephson junctions whose critical current can be controlled by field-effect gates. These junctions combine the tunability of semiconductor Josephson junctions with the high critical currents and low contact resistances of metal SNS junctions. By using local gates, the SQUID junction critical currents can be modified individually and this allows the sensitivity and symmetry of the SQUID to be controlled in-situ. We compare the critical current of the SQUID with simulations that include a non-sinusoidal current phase relation in the junctions, as expected for ballistic graphene junctions. We also investigate the transfer function of the device in both symmetric and asymmetric configurations and find a highest transfer function of 300 μV/Φ0. Graphene Josephson junctions have the potential to add functionality to existing technologies; for example, to make SQUID magnetometers with tunable sensitivity or superconducting qubits with fast electrical control.