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 Communications Technology and Electronics

Estimation of the sensitivity of bolometers operating at the edge of the superconducting transition

Alexander N. Vystavkin, А. Г. Коваленко, I. A. Kon

Published Apr 1, 2007• 1 citation
Publisher

Abstract

The well-known electron energy balance equation for a hot-electron bolometer operating at the edge of the superconducting transition is generalized to the case in which the hot-electron power outflow by means of the electric current to an external bias electric circuit must be taken into account. The equation modified in this way gives a better insight into the bolometer operation mechanism and allows evaluation of the effect of the above-mentioned power outflow on the bolometer sensitivity.

DOI
10.1134/s1064226907040122

Related papers

Rigorous Analysis of a Superconducting Hot-Electron Bolometer Mixer: Theory and Comparison with Experiment

Rainer S. Nebosis, Alexei D. Semenov, Yu. P. Gousev +1 more

We present theoretical analysis of the performance of a superconducting hot-electron bolometer mixer with electron cooling due to electron phonon interaction. The analysis is based on a complete set of thermal balance equations for phonons and electrons. A non-thermal action of a dc current has been considered phenomenologically using an analytical fit of isothermal current-voltage characteristics of the mixer. The operation point of the mixer has been determined as a result of the heating by both the power of a local oscillator and the power dissipated by the current. Electron temperature fluctuations, Nyquist noise, and shot noise have been supposed to only contribute to the mixer noise. The conversion gain and the noise temperature of the mixer have been evaluated taking into account an electro-thermal feedback between the mixer and an intermediate frequency circuit with an arbitrary impedance. We have obtained general expressions for the conversion gain, noise temperature and impedance which enabled us to estimate ultimate performance of a superconducting hot-electron bolometer mixer. Theoretical predictions are in good agreement with experimental results obtained for a NbN hot-electron bolometer mixer at a radiation frequency of 2.5 THz.

Softwaretechnik-Trends•Mar 1, 1996•21 citations

Noise properties of high-T c superconducting transition edge bolometers with electrothermal feedback

I. A. Khrebtov, Konstantin V. Ivanov, V. G. Malyarov

Numerical and experimental modeling of the characteristics (sensitivity, constant time, noise properties) of high-Tc transition edge superconducting bolometers, operating in the various modes with an electrothermal feedback, are carried out: the mode with constant bias current, i.e. passive positive electrothermal feedback, the mode with constant bias voltage, i.e. passive negative electrothermal feedback and the mode with active electronic negative electrothermal feedback . It is shown, that in the modes with negative electrothermal feedback it is possible essentially to reduce constant time of bolometers till 5-15 of times in at some prize of the noise equivalent power on high frequencies. The estimation of influence of various noise components on a performance of the bolometers, operating with positive or negative electrothermal feedbacks, is carried out at the variation of bolometer parameters.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 7, 2007•1 citation

A Hot Spot Mixer Model for Superconducting Phonon-Cooled HEB Far Above the Quasiparticle Bandgap

Harald Merkel, P. Khosropanah, Pavel A. Yagoubov +1 more

Abstract — A hot spot mixer model for phonon cooled hot electron bolometers is set up to accurately determine the dependence of the bolometer resistance on bias and absorbed LO power. An one-dimensional power balance for the nonequilibrium electrons containing an electron heat conduction term along the film and a loss term due to phonon escape to the substrate is solved. In the device's operating region of interest the absorbed heating power is usually large enough to heat a part of the bolometer bridge above the critical temperature forming a normal conducting hot spot. In this model heating due to the LO is assumed to be uniform whereas bias heating takes place in the hot spot region only. Solving the nonlinear power balance for the hot spot length allows to predict current-voltage characteristics, required heating powers and regions of optimal operation. Applying a small signal model in a given operating point yields an estimate for the intrinsic conversion gain. I. LARGE SIGNAL MODEL Existing device models for hot electron bolometers [1,2] treat the bolometer as a lumped element. It is assigned an effective temperature for the phonons and another for the electrons at a given bath temperature. In terms of heating bias power and RF power are equivalent and exchangeable. From this a method [3,4] to calculate the absorbed RF power is derived. This method is referred to as "isotherm " method: Operating points with identical device resistance must have identical temperatures since R(To„,,(,,, ) is a single valued monotonous function. Identical temperature implies identical power losses and identical 592

Softwaretechnik-Trends•Mar 1, 1999•5 citations

A hot-electron direct detector for radioastronomy

Boris S. Karasik, William R. McGrath, Henry George LeDuc +1 more

A hot-electron transition-edge superconducting bolometer with adjustable thermal relaxation speed is proposed. The bolometer contacts are made from a superconductor with high critical temperature which blocks the thermal diffusion of hot carriers into the contacts. Thus electron-phonon interaction is the only mechanism for heat removal. The speed of thermal relaxation for hot electrons in a nanometre-size superconducting bolometer with T c = 100-300 mK is controlled by the elastic electron mean free path l . The relaxation rate behaves as T 4 l at subkelvin temperatures and can be reduced by a factor of 10-100 by decreasing l . Then an antenna- or waveguide-coupled bolometer with a time constant ~10 -3 -10 -4 s will exhibit photon-noise-limited performance at millimetre and submillimetre wavelengths. The bolometer will have a figure of merit NEP 1/2 = 10 -23 -10 -22 J -1 at 100 mK which is 10 3 -10 4 times better (i.e. smaller) than that of a state-of-the-art bolometer. A tremendous increase in speed and sensitivity will have a significant impact for observational mapping applications.

Superconductor Science and Technology•Nov 1, 1999•41 citations

An accurate calculation method of the absorbed LO power in hot electron bolometric mixers

H. Merkel, Pavel A. Yagoubov, P. Khosropanah +1 more

Based on a one dimensional heat transport equation for the electrons in a superconducting hot electron bolometer, a model for a hot spot mixer is set up. The heating due to a DC bias is limited to the hot spot region where the LO power is absorbed uniformly. This gives rise to a novel measurement method for the absorbed LO power.

IEEE International Conference on Terahertz Electronics (THz)•Nov 27, 2002•3 citations

A superconducting bolometer with strong electrothermal feedback

Adrian Tae-Jin Lee, Paul L. Richards, Sae Woo Nam +2 more

We present a theoretical analysis and experimental evaluation of a transition-edge superconducting bolometer for detecting infrared and millimeter waves. The superconducting film is voltage biased and the current is read by a superconducting quantum interference device ammeter. Strong electrothermal feedback maintains the sensor temperature within the transition, gives a current responsivity that is simply the inverse of the bias voltage, and reduces the response time by several orders of magnitude below the intrinsic time constant C/G. We evaluated a voltage-biased bolometer that operates on the Tc∼95 mK transition of a tungsten film with a thermal conductance of G∼1.2×10−9 W/K. As expected, the electrical noise equivalent power of 3.3×10−17/W√Hz is close to the thermal fluctuation noise limit and is lower than that of other technologies for these values of G and temperature. The measured time constant of 10 μs is ∼100 times faster than the intrinsic time constant.

Applied Physics Letters•Sep 16, 1996•200 citations
The well-known electron energy balance equation for a hot-electron bolometer operating at the edge of the superconducting transition is generalized to the case in which the hot-electron power outflow by means of the electric current to an external bias electric circuit must be taken into account. The equation modified in this way gives a better insight into the bolometer operation mechanism and allows evaluation of the effect of the above-mentioned power outflow on the bolometer sensitivity.
We present theoretical analysis of the performance of a superconducting hot-electron bolometer mixer with electron cooling due to electron phonon interaction. The analysis is based on a complete set of thermal balance equations for phonons and electrons. A non-thermal action of a dc current has been considered phenomenologically using an analytical fit of isothermal current-voltage characteristics of the mixer. The operation point of the mixer has been determined as a result of the heating by both the power of a local oscillator and the power dissipated by the current. Electron temperature fluctuations, Nyquist noise, and shot noise have been supposed to only contribute to the mixer noise. The conversion gain and the noise temperature of the mixer have been evaluated taking into account an electro-thermal feedback between the mixer and an intermediate frequency circuit with an arbitrary impedance. We have obtained general expressions for the conversion gain, noise temperature and impedance which enabled us to estimate ultimate performance of a superconducting hot-electron bolometer mixer. Theoretical predictions are in good agreement with experimental results obtained for a NbN hot-electron bolometer mixer at a radiation frequency of 2.5 THz.
Numerical and experimental modeling of the characteristics (sensitivity, constant time, noise properties) of high-Tc transition edge superconducting bolometers, operating in the various modes with an electrothermal feedback, are carried out: the mode with constant bias current, i.e. passive positive electrothermal feedback, the mode with constant bias voltage, i.e. passive negative electrothermal feedback and the mode with active electronic negative electrothermal feedback . It is shown, that in the modes with negative electrothermal feedback it is possible essentially to reduce constant time of bolometers till 5-15 of times in at some prize of the noise equivalent power on high frequencies. The estimation of influence of various noise components on a performance of the bolometers, operating with positive or negative electrothermal feedbacks, is carried out at the variation of bolometer parameters.
Abstract — A hot spot mixer model for phonon cooled hot electron bolometers is set up to accurately determine the dependence of the bolometer resistance on bias and absorbed LO power. An one-dimensional power balance for the nonequilibrium electrons containing an electron heat conduction term along the film and a loss term due to phonon escape to the substrate is solved. In the device's operating region of interest the absorbed heating power is usually large enough to heat a part of the bolometer bridge above the critical temperature forming a normal conducting hot spot. In this model heating due to the LO is assumed to be uniform whereas bias heating takes place in the hot spot region only. Solving the nonlinear power balance for the hot spot length allows to predict current-voltage characteristics, required heating powers and regions of optimal operation. Applying a small signal model in a given operating point yields an estimate for the intrinsic conversion gain. I. LARGE SIGNAL MODEL Existing device models for hot electron bolometers [1,2] treat the bolometer as a lumped element. It is assigned an effective temperature for the phonons and another for the electrons at a given bath temperature. In terms of heating bias power and RF power are equivalent and exchangeable. From this a method [3,4] to calculate the absorbed RF power is derived. This method is referred to as "isotherm " method: Operating points with identical device resistance must have identical temperatures since R(To„,,(,,, ) is a single valued monotonous function. Identical temperature implies identical power losses and identical 592
A hot-electron transition-edge superconducting bolometer with adjustable thermal relaxation speed is proposed. The bolometer contacts are made from a superconductor with high critical temperature which blocks the thermal diffusion of hot carriers into the contacts. Thus electron-phonon interaction is the only mechanism for heat removal. The speed of thermal relaxation for hot electrons in a nanometre-size superconducting bolometer with T c = 100-300 mK is controlled by the elastic electron mean free path l . The relaxation rate behaves as T 4 l at subkelvin temperatures and can be reduced by a factor of 10-100 by decreasing l . Then an antenna- or waveguide-coupled bolometer with a time constant ~10 -3 -10 -4 s will exhibit photon-noise-limited performance at millimetre and submillimetre wavelengths. The bolometer will have a figure of merit NEP 1/2 = 10 -23 -10 -22 J -1 at 100 mK which is 10 3 -10 4 times better (i.e. smaller) than that of a state-of-the-art bolometer. A tremendous increase in speed and sensitivity will have a significant impact for observational mapping applications.
We present a theoretical analysis and experimental evaluation of a transition-edge superconducting bolometer for detecting infrared and millimeter waves. The superconducting film is voltage biased and the current is read by a superconducting quantum interference device ammeter. Strong electrothermal feedback maintains the sensor temperature within the transition, gives a current responsivity that is simply the inverse of the bias voltage, and reduces the response time by several orders of magnitude below the intrinsic time constant C/G. We evaluated a voltage-biased bolometer that operates on the Tc∼95 mK transition of a tungsten film with a thermal conductance of G∼1.2×10−9 W/K. As expected, the electrical noise equivalent power of 3.3×10−17/W√Hz is close to the thermal fluctuation noise limit and is lower than that of other technologies for these values of G and temperature. The measured time constant of 10 μs is ∼100 times faster than the intrinsic time constant.