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

Superconducting Bolometers: High-Tc and low-Tc

P L Richards

Published Jul 22, 2024• 0 citations
OpenAlex

Abstract

A description is given of recent work at Berkeley on superconducting detectors and mixers for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high-Tc superconductor YBCO from 750 GHz to 21 THz. The next report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Then, there are reports on the design and experimental performance of two different types of high-Tc bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer. The properties of a low-Tc microbolometer are also described. The last reports describe accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory.

Related papers

Superconducting bolometers: high-Tc and low-Tc

Paul L. Richards

A description is given of recent work at Berkeley on superconducting detectors and mixers for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high-Tc superconductor YBCO from 750 GHz to 21 THz. The next report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Reports are also included on the design and experimental performance of two different types of high-Tc bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer. The properties of a low-Tc microbolometer are also described. The last reports describe accurate measurements and also theoretical modeling of an SIS quasi-particle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jul 1, 1991•3 citations

Recent Developments in Superconducting Receivers

Paul L. Richards

A description is given of recent work at Berkeley on superconducting mixers and detectors for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. The next report describes accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high {Tc} superconductor YBCO from 750 GHz to 21 THz. Finally, there are reports on the design and experimental performance of two different types of high {Tc} bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer.

•Sep 1, 1990•0 citations

Gain-Bandwidth Characteristics of High-Tc Superconducting Millimeter-Wave Hot-Electron Bolometer Mixers

Chao-Te Li, Bascom S. Deaver, Robert M. Weikle +3 more

The conversion gain bandwidth characteristics of millimeter-wave mixers using high-Tc superconducting YBa2Cu307 (YBCO) thin films are presented. The YBCO films are patterned into latticecooled hot-electron bolometers (HEB) coupled to an integrated antenna and transmission line. Direct heterodyne and homodyne down-conversion measurements using local-oscillator frequencies of 75 GHz and 585 GHz show overall conversion gains of -35 dB, which includes a -18 dB coupling loss. The gain bandwidth shows a simple Lorentzian roll-off with -3 dB point of 5 to 8 GHz. No second plateau in the gain spectrum has been observed, in contrast to other reports. The effective volume of the HEB is believed to be significantly smaller than the physical dimensions of the device. Gershenzon, et al. 1 first proposed the design of a lattice-cooled superconducting hot-electron bolometer (HEB) for use as a low-power, wide-band-width heterodyne mixer at millimeter and submillimeter-wave frequencies. This idea has been successfully implemented using NbN , which shows a conversion gain as high as -15 dB using 1 1.tW of pump power at a temperature of 4.2 K. The ultimate speed and bandwidth of the lattice-cooled HEB is determined by the electron-phonon scattering rate. For this reason, Gershenzon 3 suggested that the high normal-state resistivity of the high-Tc superconductor YBa2Cu307 (YBCO) could indicate a very fast electron inelastic scattering, rate and so make this material an ideal candidate to produce a very wide instantaneous bandwidth lattice-cooled HEB operating at 77 K. The first reports of such mixers at 1.5 gm (Ref. 4) and 9.6 gm (Ref. 5) wavelengths showed a very low intrinsic conversion gain of -77 dB (excluding coupling losses) using a relatively large 0.3 mW of absorbed LO power. However, the gain bandwidth showed a twoplateau structure. A low frequency plateau near -77 dB rolled off near 1 GHz intermediate frequency (IF) but gave way to a second plateau near -90 dB that extended to at least 18 GHz, the upper limit of the measurement. Karasik, et al., have done extensive calculations on the conversion gain properties of lattice-cooled HEB mixers for different mixer dimensions, using a two-temperature model. They found that the conversion gain increases

•Mar 1, 1998•1 citation

High-Tc superconducting microbolometer for terahertz applications

C. Ulysse, Alain Gaugue, Aurèle J. L. Adam +3 more

\nSuperconducting hot electron bolometer mixers are now a competitive alternative to Schottky diode mixers in the terahertz frequency range because of their ultra wideband (from millimeter waves to visible light), high conversion gain, and low intrinsic noise level. High Tc superconductor materials can be used to make hot electron bolometers and present some advantage in term of operating temperature and cooling. In this paper, we present first a model for the study of superconducting hot electron bolometers responsivity in direct detection mode, in order to establish a firm basis for the design of future THz mixers. Secondly, an original process to realize YBaCuO hot electron bolometer mixers will be described. Submicron YBaCuO superconducting structures are expitaxially sputter deposited on MgO substrates and patterned by using electron beam lithography in combination with optical lithography. Metal masks achieved by electron beam lithography are insuring a good bridge definition and protection during ion etching. Finally, detection experiments are being performed with a laser at 850 nm wavelength, in homodyne mode in order to prove the feasibility and potential performances of these devices.\n

Journal de Physique IV (Proceedings)•May 1, 2002•1 citation

YBCO HEB THz mixers

Arvid Hammar, Serguei Cherednichenko, Stella Bevilacqua

We report on an experimental investigation of high-Tc superconducting hot electron bolometer (HEB) mixers of YBCO. These mixers were tested at 100 and 530 GHz LO for a range of temperatures around 77 K. The conversion gain of -32 dB was measured at an LO power of about 1 mW (530 GHz) and 0.3 GHz IF. The mixers were integrated with a logarithmic spiral antenna on a silicon lens, providing a broad frequency coverage (well above 1 THz). To measure the incident RF signal power we used the homodyne responsivity (see abstract "Terahertz response of YBCO HEB homodyne detectors") which is referenced to the input of the silicon lens where the bolometers were glued. Corrections were made for losses in the cryostat window and polarization losses between the signal and antenna. We made the measurements at different temperatures and different LO power levels which were measured using a quasi optical detector at room temperature. The 3 dB gain bandwidth was measured to be about 0.2 GHz. The bolometer bridges have nominal dimensions 1 μm x 2 μm x 50 nm and are fabricated on sapphire substrates using UV photolithography. Backward wave oscillators sources were used at 530 GHz and Gunn diodes at 100 GHz.

•Jan 1, 2011•0 citations

New designs for antenna-coupled superconducting bolometers

J. Mees, Michael Nahum, P. L. Richards

We propose a novel antenna-coupled low Tc superconducting bolometer which makes use of the thermal boundary resistance and the trapping of quasiparticles at metal-superconducting interfaces. A thin strip of superconductor, whose temperature is regulated at the midpoint of its resistive transition, serves both as a resistive load to thermalize the infrared current from the antenna and as a thermometer to measure the resulting temperature rise. Calculations give a noise equivalent power (NEP)≊7×10−16 T5/2 WHz−1/2 and a time constant τ≊10−8 T−2 s for a 2×2 μm2 thermometer area at temperature T (K). Designs for efficient on-chip rf matching and filter networks with well-defined bandpasses are presented. These detectors can be used to make frequency-multiplexed array receivers for astronomical observations at near millimeter wavelengths.

Applied Physics Letters•Oct 28, 1991•38 citations
A description is given of recent work at Berkeley on superconducting detectors and mixers for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high-Tc superconductor YBCO from 750 GHz to 21 THz. The next report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Then, there are reports on the design and experimental performance of two different types of high-Tc bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer. The properties of a low-Tc microbolometer are also described. The last reports describe accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory.
A description is given of recent work at Berkeley on superconducting detectors and mixers for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high-Tc superconductor YBCO from 750 GHz to 21 THz. The next report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Reports are also included on the design and experimental performance of two different types of high-Tc bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer. The properties of a low-Tc microbolometer are also described. The last reports describe accurate measurements and also theoretical modeling of an SIS quasi-particle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory.
A description is given of recent work at Berkeley on superconducting mixers and detectors for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. The next report describes accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high {Tc} superconductor YBCO from 750 GHz to 21 THz. Finally, there are reports on the design and experimental performance of two different types of high {Tc} bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer.
The conversion gain bandwidth characteristics of millimeter-wave mixers using high-Tc superconducting YBa2Cu307 (YBCO) thin films are presented. The YBCO films are patterned into latticecooled hot-electron bolometers (HEB) coupled to an integrated antenna and transmission line. Direct heterodyne and homodyne down-conversion measurements using local-oscillator frequencies of 75 GHz and 585 GHz show overall conversion gains of -35 dB, which includes a -18 dB coupling loss. The gain bandwidth shows a simple Lorentzian roll-off with -3 dB point of 5 to 8 GHz. No second plateau in the gain spectrum has been observed, in contrast to other reports. The effective volume of the HEB is believed to be significantly smaller than the physical dimensions of the device. Gershenzon, et al. 1 first proposed the design of a lattice-cooled superconducting hot-electron bolometer (HEB) for use as a low-power, wide-band-width heterodyne mixer at millimeter and submillimeter-wave frequencies. This idea has been successfully implemented using NbN , which shows a conversion gain as high as -15 dB using 1 1.tW of pump power at a temperature of 4.2 K. The ultimate speed and bandwidth of the lattice-cooled HEB is determined by the electron-phonon scattering rate. For this reason, Gershenzon 3 suggested that the high normal-state resistivity of the high-Tc superconductor YBa2Cu307 (YBCO) could indicate a very fast electron inelastic scattering, rate and so make this material an ideal candidate to produce a very wide instantaneous bandwidth lattice-cooled HEB operating at 77 K. The first reports of such mixers at 1.5 gm (Ref. 4) and 9.6 gm (Ref. 5) wavelengths showed a very low intrinsic conversion gain of -77 dB (excluding coupling losses) using a relatively large 0.3 mW of absorbed LO power. However, the gain bandwidth showed a twoplateau structure. A low frequency plateau near -77 dB rolled off near 1 GHz intermediate frequency (IF) but gave way to a second plateau near -90 dB that extended to at least 18 GHz, the upper limit of the measurement. Karasik, et al., have done extensive calculations on the conversion gain properties of lattice-cooled HEB mixers for different mixer dimensions, using a two-temperature model. They found that the conversion gain increases
\nSuperconducting hot electron bolometer mixers are now a competitive alternative to Schottky diode mixers in the terahertz frequency range because of their ultra wideband (from millimeter waves to visible light), high conversion gain, and low intrinsic noise level. High Tc superconductor materials can be used to make hot electron bolometers and present some advantage in term of operating temperature and cooling. In this paper, we present first a model for the study of superconducting hot electron bolometers responsivity in direct detection mode, in order to establish a firm basis for the design of future THz mixers. Secondly, an original process to realize YBaCuO hot electron bolometer mixers will be described. Submicron YBaCuO superconducting structures are expitaxially sputter deposited on MgO substrates and patterned by using electron beam lithography in combination with optical lithography. Metal masks achieved by electron beam lithography are insuring a good bridge definition and protection during ion etching. Finally, detection experiments are being performed with a laser at 850 nm wavelength, in homodyne mode in order to prove the feasibility and potential performances of these devices.\n
We report on an experimental investigation of high-Tc superconducting hot electron bolometer (HEB) mixers of YBCO. These mixers were tested at 100 and 530 GHz LO for a range of temperatures around 77 K. The conversion gain of -32 dB was measured at an LO power of about 1 mW (530 GHz) and 0.3 GHz IF. The mixers were integrated with a logarithmic spiral antenna on a silicon lens, providing a broad frequency coverage (well above 1 THz). To measure the incident RF signal power we used the homodyne responsivity (see abstract "Terahertz response of YBCO HEB homodyne detectors") which is referenced to the input of the silicon lens where the bolometers were glued. Corrections were made for losses in the cryostat window and polarization losses between the signal and antenna. We made the measurements at different temperatures and different LO power levels which were measured using a quasi optical detector at room temperature. The 3 dB gain bandwidth was measured to be about 0.2 GHz. The bolometer bridges have nominal dimensions 1 μm x 2 μm x 50 nm and are fabricated on sapphire substrates using UV photolithography. Backward wave oscillators sources were used at 530 GHz and Gunn diodes at 100 GHz.
We propose a novel antenna-coupled low Tc superconducting bolometer which makes use of the thermal boundary resistance and the trapping of quasiparticles at metal-superconducting interfaces. A thin strip of superconductor, whose temperature is regulated at the midpoint of its resistive transition, serves both as a resistive load to thermalize the infrared current from the antenna and as a thermometer to measure the resulting temperature rise. Calculations give a noise equivalent power (NEP)≊7×10−16 T5/2 WHz−1/2 and a time constant τ≊10−8 T−2 s for a 2×2 μm2 thermometer area at temperature T (K). Designs for efficient on-chip rf matching and filter networks with well-defined bandpasses are presented. These detectors can be used to make frequency-multiplexed array receivers for astronomical observations at near millimeter wavelengths.