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

Journal of Applied Physics

Submillimeter detector operation of granular superconducting NbN films

G. L. Carr, David R. Karecki, Sidney Perkowitz

Published May 15, 1984• 7 citations
Publisher

Abstract

Detection of submillimeter radiation between 10 and 40 cm−1 (300–1200 GHz) has been carried out with a high resistance granular NbN film (R⧠= 8440 Ω/⧠) below 6 K with evidence of Josephson-like operation. The nonoptimized detector sensitivity and noise equivalent power at 17.5 cm−1 (525 GHz) were about 20 V/W and 5×10−8 W/Hz1/2, respectively, comparable to values obtained with granular Sn and Pb.

DOI
10.1063/1.332908

Related papers

Josephson behavior in granular NbN weak links

J. H. Claassen

A substrate step technique has been used to fabricate superconducting NbN weak links of length ∼750 Å, width ∼1.5 μm. The film in the weak-link region is less than 100 Å thick, and shows evidence of being granular. These devices have very high resistance (as much as 30 Ω), are quite rugged, and show almost ideal Josephson response to microwave radiation at 70 GHz. A vortex flow model is expected to apply because of the small coherence length in the weak-link material. However, the well-known resistively shunted junction model is found to be a significantly better predictor of device behavior.

Applied Physics Letters•May 1, 1980•29 citations

Granular superconducting NbN films as submillimeter detectors

G. L. Carr, David R. Karecki, Sidney Perkowitz

Non-bolometric detection is observed in granular superconducting NbN films. Detection, related to the non-linear I-V's, occures over a large bias range. Preliminary results give a sensitivity of 20 V/W and NEP of 5×10−6W at 4 K. Granular NbN films show no apparent degradation with time.

International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)•Dec 1, 1983•0 citations

Superconductive bolometers for submillimeter wavelengths

John L. Clarke, G. I. Hoffer, P. L. Richards +1 more

Three types of composite superconductive bolometers are described in which the temperature-sensitive element is a superconducting film at the transition temperature, a superconductor–normal metal–superconductor Josephson junction, or a superconductor–insulator–normal metal quasiparticle tunneling junction. The temperature-sensitive element is evaporated onto a sapphire substrate on the reverse side of which is a bismuth film to absorb the submillimeter radiation. The noise limitations of each type of bolometer are calculated. The fabrication and measured performance of the transition-edge bolometer and the Josephson-junction bolometer are described. The best electrical (noise-equivalent power) NEP obtained with a transition-edge bolometer fabricated on a 4×4×0.005-mm sapphire substrate is (1.7±0.1) ×10−15 W Hz−1/2 at 2 Hz at an operating temperature of 1.27 K. This NEP is within a factor of 2 of the thermal noise limit. The effective absorptivity of the bismuth film is measured to be 0.47±0.05, and the corresponding detectivity D* is calculated to be (1.1±0.1) ×1014 cm W−1 Hz1/2. Suggestions are made for further improvements in sensitivity.

Journal of Applied Physics•Dec 1, 1977•139 citations

Sensitivity and gigahertz counting performance of NbN superconducting single-photon detectors

Alexander A. Korneev, Pavel B. Kouminov, V. Matvienko +12 more

We have measured the quantum efficiency (QE), GHz counting rate, jitter, and noise-equivalent power (NEP) of nanostructured NbN superconducting single-photon detectors (SSPDs) in the visible to infrared radiation range. Our 3.5-nm-thick and 100- to 200-nm-wide meander-type devices (total area 10×10μm2), operating at 4.2K, exhibit an experimental QE of up to 20% in the visible range and ∼10% at 1.3 to 1.55μm wavelength and are potentially sensitive up to midinfrared (∼10μm) radiation. The SSPD counting rate was measured to be above 2GHz with jitter <18ps, independent of the wavelength. The devices’ NEP varies from ∼10−17W∕Hz1∕2 for 1.55μm photons to ∼10−20W∕Hz1∕2 for visible radiation. Lowering the SSPD operating temperature to 2.3K significantly enhanced its performance, by increasing the QE to ∼20% and lowering the NEP level to ∼3×10−22W∕Hz1∕2, both measured at 1.26μm wavelength.

Applied Physics Letters•Jun 22, 2004•194 citations

Use of granular NbN as a superconducting bolometer

Kurt Weiser, Ulrich Strom, S. A. Wolf +1 more

An ultrathin film of granular NbN is used as a superconducting bolometer. The bolometer has a high operating temperature (∼12 K), is very sensitive (∼5000 Ω/deg), and exhibits a fast thermal response time, which is estimated to be less than 10−10 sec.

Journal of Applied Physics•Jul 1, 1981•35 citations

Broadband ultrafast superconducting NbN detector for electromagnetic radiation

Yu. P. Gousev, Gregory N Gol'tsman, A. D. Semenov +4 more

An ultrafast detector that is sensitive to radiation in a broad spectral range from submillimeter waves to visible light is reported. It consists of a structured NbN thin film cooled to a temperature below Tc (∼11 K). Using 20 ps pulses of a GaAs laser, we observed signal pulses with both rise and decay time of about 50 ps. From the analysis of a mixing experiment with submillimeter radiation we estimate an intrinsic response time of the detector of ∼12 ps. The sensitivity was found to be similar for the near-infrared and submillimeter radiation. Broadband sensitivity and short response time are attributed to a quasiparticle heating effect.

Journal of Applied Physics•Apr 1, 1994•113 citations
Detection of submillimeter radiation between 10 and 40 cm−1 (300–1200 GHz) has been carried out with a high resistance granular NbN film (R⧠= 8440 Ω/⧠) below 6 K with evidence of Josephson-like operation. The nonoptimized detector sensitivity and noise equivalent power at 17.5 cm−1 (525 GHz) were about 20 V/W and 5×10−8 W/Hz1/2, respectively, comparable to values obtained with granular Sn and Pb.
A substrate step technique has been used to fabricate superconducting NbN weak links of length ∼750 Å, width ∼1.5 μm. The film in the weak-link region is less than 100 Å thick, and shows evidence of being granular. These devices have very high resistance (as much as 30 Ω), are quite rugged, and show almost ideal Josephson response to microwave radiation at 70 GHz. A vortex flow model is expected to apply because of the small coherence length in the weak-link material. However, the well-known resistively shunted junction model is found to be a significantly better predictor of device behavior.
Three types of composite superconductive bolometers are described in which the temperature-sensitive element is a superconducting film at the transition temperature, a superconductor–normal metal–superconductor Josephson junction, or a superconductor–insulator–normal metal quasiparticle tunneling junction. The temperature-sensitive element is evaporated onto a sapphire substrate on the reverse side of which is a bismuth film to absorb the submillimeter radiation. The noise limitations of each type of bolometer are calculated. The fabrication and measured performance of the transition-edge bolometer and the Josephson-junction bolometer are described. The best electrical (noise-equivalent power) NEP obtained with a transition-edge bolometer fabricated on a 4×4×0.005-mm sapphire substrate is (1.7±0.1) ×10−15 W Hz−1/2 at 2 Hz at an operating temperature of 1.27 K. This NEP is within a factor of 2 of the thermal noise limit. The effective absorptivity of the bismuth film is measured to be 0.47±0.05, and the corresponding detectivity D* is calculated to be (1.1±0.1) ×1014 cm W−1 Hz1/2. Suggestions are made for further improvements in sensitivity.
We have measured the quantum efficiency (QE), GHz counting rate, jitter, and noise-equivalent power (NEP) of nanostructured NbN superconducting single-photon detectors (SSPDs) in the visible to infrared radiation range. Our 3.5-nm-thick and 100- to 200-nm-wide meander-type devices (total area 10×10μm2), operating at 4.2K, exhibit an experimental QE of up to 20% in the visible range and ∼10% at 1.3 to 1.55μm wavelength and are potentially sensitive up to midinfrared (∼10μm) radiation. The SSPD counting rate was measured to be above 2GHz with jitter <18ps, independent of the wavelength. The devices’ NEP varies from ∼10−17W∕Hz1∕2 for 1.55μm photons to ∼10−20W∕Hz1∕2 for visible radiation. Lowering the SSPD operating temperature to 2.3K significantly enhanced its performance, by increasing the QE to ∼20% and lowering the NEP level to ∼3×10−22W∕Hz1∕2, both measured at 1.26μm wavelength.
An ultrafast detector that is sensitive to radiation in a broad spectral range from submillimeter waves to visible light is reported. It consists of a structured NbN thin film cooled to a temperature below Tc (∼11 K). Using 20 ps pulses of a GaAs laser, we observed signal pulses with both rise and decay time of about 50 ps. From the analysis of a mixing experiment with submillimeter radiation we estimate an intrinsic response time of the detector of ∼12 ps. The sensitivity was found to be similar for the near-infrared and submillimeter radiation. Broadband sensitivity and short response time are attributed to a quasiparticle heating effect.