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

Superconductor Science and Technology

Investigation of dark count rate in NbRe microstrips for single photon detection

Pasquale Ercolano, C. Cirillo, Mikkel Ejrnaes, Federico Chianese, Daniela Salvoni, Ciro Bruscino, Roberta Satariano, A. Cassinese, C. Attanasio, Giovanni Piero Pepe, L. Parlato

Published Aug 21, 2023• 7 citations
Publisher

Abstract

Abstract Superconducting microstrip single photon detectors (SMSPDs) received great interest since they are expected to combine the excellent performance of superconducting nanostrip single photon detectors with the possibility to cover large active areas using low-cost fabrication techniques. In this work, we fabricated SMSPDs based on NbRe to investigate the role of vortices in the dark counts events in this innovative material and in devices with micrometer size. We realized devices with different layouts, namely single microstrips and pairs of parallel microstrips. The energy barriers related to the motion of single vortices or vortex–antivortex pairs, responsible of detection events, have been determined and compared with the ones of similar devices based on different materials, such as MoSi, WSi and NbN. The analysis confirms the high potential of NbRe for the realization of superconducting single photon detectors with large areas.

DOI
10.1088/1361-6668/acf24a

Related papers

Research Progress of Superconducting Microstrips Single-Photon Detectors

Fei Li, Jinji Zheng, 邓志威

Superconducting microstrips single-photon detectors (SMSPDs) are a novel type of single-photon sensor based on superconducting thin films patterned into micrometer-scale strip widths. Compared with superconducting nanowire single-photon detectors (SNSPDs), SMSPDs not only substantially lower the fabrication dependence on high-precision electron-beam lithography, but also exhibit lower kinetic inductance, higher bias current, and weaker polarization sensitivity. These advantages pave a new route toward superconducting single-photon detection systems with large active areas and low dark-count rates. Because of their performance, SMSPDs exhibit tremendous application potential in cutting-edge fields such as quantum communication, LiDAR, dark-matter searches, and high-energy particle detection. Accordingly, this paper provides a systematic review of recent advances in SMSPD research, covering the underlying physical mechanisms, material systems, geometrical design, readout circuitry, and application domains. Firstly, this review elaborates on the photon response mechanism of SMSPDs and clarifies its correlation with vortex dynamics. Secondly, this review categorizes the superconducting materials used for SMSPD fabrication and analyzes the influences of characteristic thin-film parameters on device performance. Furthermore, this work concludes the evolution and optimization strategies of geometrical design and readout circuit schemes for SMSPDs, and presents the current application status. Finally, we offer perspectives on its future development trajectory. This review provides a foundation in physical mechanisms and design guidance for the development of large active area SMSPDs with high efficiency and low dark counts.

Sensors•Oct 27, 2026•0 citations

Single photon detection up to 2 µm in pair of parallel microstrips based on NbRe ultrathin films

C. Cirillo, Mikkel Ejrnaes, Pasquale Ercolano +6 more

Superconducting microstrip single photon detectors (SMSPDs) are increasingly attracting the interest of the scientific community as a new platform for large area detectors with unprecedented advantaged in terms of fabrication. However, while their operativity at the telecommunication wavelength was achieved, working beyond 1.55 µm is challenging. Here, we experimentally demonstrate single-photon operation of NbRe microstrips at wavelengths of 1.55 and 2 µm. The devices are structured as pairs of parallel microstrips with widths ranging from 1.4 to 2.2 μm and lengths from 5 to 10 μm. This innovative design may assure large sensitive areas, without affecting the kinetic inductance, namely the time performance of the detectors. The results are discussed in the framework of the hot-spot two-temperature model.

arXiv:2409.02619•Scientific Reports•Sep 2, 2024•10 citations

Characterization of a Hole-Patterned Microstrip Superconducting Single-Photon Detector

Feiyan Li, Xiang Pan, Qi Chen +3 more

Superconducting microstrip single-photon detectors (SMSPDs) with near-infrared sensitivity have significant advantages in terms of high quantum efficiency and low dark counts in a large active area. Hole-patterned superconductor microstrips have been reported for fast and efficient single-photon detection. In this work, we fabricated and characterized hole-patterned microstrips with different hole diameters on 5 nm thick MoSi films and an area of 500 × 500 μm2. We observed that the count rate curves of detectors 2 and 3 with holes tend to saturate slightly, whereas those of detector 1 without holes do not. Furthermore, the dark count is similar between detector 1 without holes and detector 2 with small holes and much lower than that of detector 3 with large holes. These experiments indicate that a proper hole is beneficial for efficiency without increasing the dark count rate.

IEEE Journal of Selected Topics in Quantum Electronics•Jan 14, 2025•2 citations

Superconducting microstrip single-photon detector with system detection efficiency over 90% at 1550 nm

Guangzhao Xu, Wei-Jun Zhang, Li-Xing You +9 more

Generally, a superconducting nanowire single-photon detector (SNSPD) is composed of wires with a typical width of ∼ 100 nm . Recent studies have found that superconducting strips with a micrometer-scale width can also detect single photons. Compared with the SNSPD covering the same area, the superconducting microstrip single-photon detector (SMSPD) has smaller kinetic inductance, higher working current, and lower requirements in fabrication accuracy, providing potential applications in the development of ultralarge active area detectors. However, the study of SMSPD is still in its infancy, and the realization of its high-performance and practical use remains an open question. This study demonstrates a NbN SMSPD with a nearly saturated system detection efficiency (SDE) of ∼ 92.2 % at a dark count rate of ∼ 200 cps , a polarization sensitivity of ∼ 1.03 , and a minimum timing jitter of ∼ 48 ps at the telecom wavelength of 1550 nm when coupled with a single-mode fiber and operated at 0.84 K. Furthermore, the detector’s SDE is over 70% when operated at a 2.1 K closed-cycle cryocooler.

arXiv:2101.05407•Photonics Research•Mar 23, 2021•68 citations

Investigation of Superconducting Molybdenum Silicide Nanostrips and Microstrips for Single Photon Detectors

L. Parlato, Daniela Salvoni, Mikkel Ejrnaes +11 more

Abstract Superconducting nanostrip single photon detectors have emerged as the highest performing single-photon detectors; however, the possibility to use superconducting microstrip as single photon detectors is very appealing both to use them as larger areas detectors and for an easier technology in the manufacturing. The aim of this work is to test the photoresponse in liquid helium dewar of 9 nm thick MoSi covered with a very thin (2 nm) layer of Al, in two different configurations: nanomeanders and microstrips. We demonstrate that MoSi/Al microstrips can work as photodetectors also at T = 4.2 K. We also compare the dark count rate of the microstrip and the nanowire, confirming the lower noise for the microstrips also at 4.2 K.

Journal of Low Temperature Physics•Sep 5, 2022•2 citations

Investigation of dark counts in innovative materials for superconducting nanowire single-photon detector applications

L. Parlato, Mikkel Ejrnaes, Umberto Nasti +9 more

The phenomenon of dark counts in nanostripes of different superconductor systems such as high-temperature superconducting YBa2Cu3O7-x and superconductor/ferromagnet hybrids consisting of either NbN/NiCu or YBa2Cu3O7- x/L0.7Sr0.3MnO3 bilayers have been investigated. For NbN/NiCu the rate of dark-count transients have been reduced with respect to pure NbN nanostripes and the events were dominated by a single vortex entry from the edge of the stripe. In the case of nanostripes based on YBa2Cu3O7-x, we have found that thermal activation of vortices was also, apparently, responsible for triggering dark-count signals.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 15, 2017•2 citations
Abstract Superconducting microstrip single photon detectors (SMSPDs) received great interest since they are expected to combine the excellent performance of superconducting nanostrip single photon detectors with the possibility to cover large active areas using low-cost fabrication techniques. In this work, we fabricated SMSPDs based on NbRe to investigate the role of vortices in the dark counts events in this innovative material and in devices with micrometer size. We realized devices with different layouts, namely single microstrips and pairs of parallel microstrips. The energy barriers related to the motion of single vortices or vortex–antivortex pairs, responsible of detection events, have been determined and compared with the ones of similar devices based on different materials, such as MoSi, WSi and NbN. The analysis confirms the high potential of NbRe for the realization of superconducting single photon detectors with large areas.
Superconducting microstrips single-photon detectors (SMSPDs) are a novel type of single-photon sensor based on superconducting thin films patterned into micrometer-scale strip widths. Compared with superconducting nanowire single-photon detectors (SNSPDs), SMSPDs not only substantially lower the fabrication dependence on high-precision electron-beam lithography, but also exhibit lower kinetic inductance, higher bias current, and weaker polarization sensitivity. These advantages pave a new route toward superconducting single-photon detection systems with large active areas and low dark-count rates. Because of their performance, SMSPDs exhibit tremendous application potential in cutting-edge fields such as quantum communication, LiDAR, dark-matter searches, and high-energy particle detection. Accordingly, this paper provides a systematic review of recent advances in SMSPD research, covering the underlying physical mechanisms, material systems, geometrical design, readout circuitry, and application domains. Firstly, this review elaborates on the photon response mechanism of SMSPDs and clarifies its correlation with vortex dynamics. Secondly, this review categorizes the superconducting materials used for SMSPD fabrication and analyzes the influences of characteristic thin-film parameters on device performance. Furthermore, this work concludes the evolution and optimization strategies of geometrical design and readout circuit schemes for SMSPDs, and presents the current application status. Finally, we offer perspectives on its future development trajectory. This review provides a foundation in physical mechanisms and design guidance for the development of large active area SMSPDs with high efficiency and low dark counts.
Superconducting microstrip single photon detectors (SMSPDs) are increasingly attracting the interest of the scientific community as a new platform for large area detectors with unprecedented advantaged in terms of fabrication. However, while their operativity at the telecommunication wavelength was achieved, working beyond 1.55 µm is challenging. Here, we experimentally demonstrate single-photon operation of NbRe microstrips at wavelengths of 1.55 and 2 µm. The devices are structured as pairs of parallel microstrips with widths ranging from 1.4 to 2.2 μm and lengths from 5 to 10 μm. This innovative design may assure large sensitive areas, without affecting the kinetic inductance, namely the time performance of the detectors. The results are discussed in the framework of the hot-spot two-temperature model.
Superconducting microstrip single-photon detectors (SMSPDs) with near-infrared sensitivity have significant advantages in terms of high quantum efficiency and low dark counts in a large active area. Hole-patterned superconductor microstrips have been reported for fast and efficient single-photon detection. In this work, we fabricated and characterized hole-patterned microstrips with different hole diameters on 5 nm thick MoSi films and an area of 500 × 500 μm2. We observed that the count rate curves of detectors 2 and 3 with holes tend to saturate slightly, whereas those of detector 1 without holes do not. Furthermore, the dark count is similar between detector 1 without holes and detector 2 with small holes and much lower than that of detector 3 with large holes. These experiments indicate that a proper hole is beneficial for efficiency without increasing the dark count rate.
Generally, a superconducting nanowire single-photon detector (SNSPD) is composed of wires with a typical width of ∼ 100 nm . Recent studies have found that superconducting strips with a micrometer-scale width can also detect single photons. Compared with the SNSPD covering the same area, the superconducting microstrip single-photon detector (SMSPD) has smaller kinetic inductance, higher working current, and lower requirements in fabrication accuracy, providing potential applications in the development of ultralarge active area detectors. However, the study of SMSPD is still in its infancy, and the realization of its high-performance and practical use remains an open question. This study demonstrates a NbN SMSPD with a nearly saturated system detection efficiency (SDE) of ∼ 92.2 % at a dark count rate of ∼ 200 cps , a polarization sensitivity of ∼ 1.03 , and a minimum timing jitter of ∼ 48 ps at the telecom wavelength of 1550 nm when coupled with a single-mode fiber and operated at 0.84 K. Furthermore, the detector’s SDE is over 70% when operated at a 2.1 K closed-cycle cryocooler.
Abstract Superconducting nanostrip single photon detectors have emerged as the highest performing single-photon detectors; however, the possibility to use superconducting microstrip as single photon detectors is very appealing both to use them as larger areas detectors and for an easier technology in the manufacturing. The aim of this work is to test the photoresponse in liquid helium dewar of 9 nm thick MoSi covered with a very thin (2 nm) layer of Al, in two different configurations: nanomeanders and microstrips. We demonstrate that MoSi/Al microstrips can work as photodetectors also at T = 4.2 K. We also compare the dark count rate of the microstrip and the nanowire, confirming the lower noise for the microstrips also at 4.2 K.
The phenomenon of dark counts in nanostripes of different superconductor systems such as high-temperature superconducting YBa2Cu3O7-x and superconductor/ferromagnet hybrids consisting of either NbN/NiCu or YBa2Cu3O7- x/L0.7Sr0.3MnO3 bilayers have been investigated. For NbN/NiCu the rate of dark-count transients have been reduced with respect to pure NbN nanostripes and the events were dominated by a single vortex entry from the edge of the stripe. In the case of nanostripes based on YBa2Cu3O7-x, we have found that thermal activation of vortices was also, apparently, responsible for triggering dark-count signals.