|   | 
Details
   web
Records
Author Trifonov, A.; Tong, C.-Y. E.; Lobanov, Y.; Kaurova, N.; Blundell, R.; Goltsman, G.
Title Gap frequency and photon absorption in a hot electron bolometer Type Conference Article
Year 2016 Publication Proc. 27th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 27th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 121
Keywords (down) NbN HEB; Si membrane
Abstract The superconducting energy gap is a crucial parameter of a superconductor when used in mixing applications. In the case of the SIS mixer, the mixing process is efficient for frequencies below the energy gap, whereas, in the case of the HEB mixer, the mixing process is most efficient at frequencies above the gap, where photon absorption takes place more readily. We have investigated the photon absorption phenomenon around the gap frequency of HEB mixers based on NbN films deposited on silicon membranes. Apart from studying the pumped I-V curves of HEB devices, we have also probed them with microwave radiation, as previously described [1]. At frequencies far below the gap frequency, the pumped I-V curves show abrupt switching between the superconducting and resistive states. For the NbN HEB mixers we tested, which have critical temperatures of ~9 K, this is true for frequencies below about 400 GHz. As the pump frequency is increased beyond 400 GHz, the resistive state extends towards zero bias and at some point a small region of negative differential resistance appears close to zero bias. In this region, the microwave probe reveals that the device impedance is changing randomly with time. As the pump frequency is further increased, this random impedance change develops into relaxation oscillations, which can be observed by the demodulation of the reflected microwave probe. Initially, these oscillations take the form of several frequencies grouped together under an envelope. As we approach the gap frequency, the multiple frequency relaxation oscillations coalesce into a single frequency of a few MHz. The resultant square-wave nature of the oscillation is a clear indication that the device is in a bi-stable state, switching between the superconducting and normal state. Above the gap frequency, it is possible to obtain a pumped I-V curve with no negative differential resistance above a threshold pumping level. Below this pumping level, the device demonstrates bi-stability, and regular relaxation oscillation at a few MHz is observed as a function of pump power. The threshold pumping level is clearly related to the amount of power absorbed by the device and its phonon cooling. From the above experiment, we can derive the gap frequency of the NbN film, which is 585 GHz for our 6 μm thin silicon membrane-based device. We also confirm that the HEB mixer is not an efficient photon absorber for radiation below the gap frequency. 1. A. Trifonov et al., “Probing the stability of HEB mixers with microwave injection”, IEEE Trans. Appl. Supercond., vol. 25, no. 3, June 2015.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1204
Permanent link to this record
 

 
Author Lobanov, Y. V.; Vakhtomin, Y. B.; Pentin, I. V.; Khabibullin, R. A.; Shchavruk, N. V.; Smirnov, K. V.; Silaev, A. A.
Title Characterization of the THz quantum cascade laser using fast superconducting hot electron bolometer Type Journal Article
Year 2018 Publication EPJ Web Conf. Abbreviated Journal EPJ Web Conf.
Volume 195 Issue Pages 04004 (1 to 2)
Keywords (down) NbN HEB, QCL
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2100-014X ISBN Medium
Area Expedition Conference 3rd International Conference “Terahertz and Microwave Radiation: Generation, Detection and Applications” (TERA-2018)
Notes Approved no
Call Number Serial 1808
Permanent link to this record
 

 
Author Gol’tsman, G. N.; Gershenzon, E. M.
Title High speed hot-electron superconducting bolometer Type Conference Article
Year 1993 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 2104 Issue Pages 181-182
Keywords (down) NbN HEb, Nb, Al
Abstract Physical limitation of response time of a superconducting bolometer as well as the nature of non-equilibrium detection of radiation have been investigated for Al, Nb and NbN thin films in spectral range from submillimeter to near-infraredwavelengths [1,2]. In the case of ideal heat removal from the film with the f_‘. 100A thickness the detection mechanism is an electron heating effect that is not selective to radiation wavelength in a very broad range. The response time ofan electron heating bolometer is determined by an electron-phonon interaction time. This time is of about 10 ns, 0.5 ns and 20 ps for Al, Nb, and NbN correspondingly near the critical temperature of the superconducting film. Thesensitive area of the bolometer consists of a number of narrow strips (with awidth of 1µm) connected in parallel to contact pads; these pads together witha sapphire substrate and a ground plate represent the microstrip transmissionline with an impedance of 50 Q.
Address
Corporate Author Thesis
Publisher SPIE Place of Publication Editor Birch, J.R.; Parker, T.J.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference 18th International Conference on Infrared and Millimeter Waves
Notes Approved no
Call Number Serial 1652
Permanent link to this record
 

 
Author Krause, S.; Mityashkin, V.; Antipov, S.; Gol'tsman, G.; Meledin, D.; Desmaris, V.; Belitsky, V.; Rudzinski, M.
Title Study of IF bandwidth of NbN hot electron bolometers on GaN buffer layer using a direct measurement method Type Conference Article
Year 2016 Publication Proc. 27th Int. Symp. Space Terahertz Technol. Abbreviated Journal
Volume Issue Pages 30-32
Keywords (down) NbN HEB, GaN buffer layer
Abstract In this paper, we present a reliable measurement method to study the influence of the GaN buffer layer on phonon-escape time in comparison with commonly used Si substrates and, in consequence, on the IF bandwidth of HEBs. One of the key aspects is to operate the HEB mixer at elevated bath temperatures close to the critical temperature of the NbN ultra-thin film, where contributions from electron-phonon processes and self-heating effects are relatively small, therefore IF roll-off will be governed by the phonon-escape.Two independent experiments were performed at GARD and MSPU on a similar experimental setup at frequencies of approximately 180 and 140 GHz, respectively, and have shown reproducible and consistent results. The entire IF chain was characterized by S-parameter measurements. We compared the measurement results of epitaxial NbN grown onto GaN buffer-layer with Tc of 12.5 K (4.5nm) with high quality polycrystalline NbN films on Si substrate with Tc of 10.5K (5nm) and observed a strong indication of an enhancement of phonon escape to the substrate by a factor of two for the NbN/GaN material combination.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1202
Permanent link to this record
 

 
Author Ren, Y.; Zhang, D. X.; Zhou, K. M.; Miao, W.; Zhang, W.; Shi, S. C.; Seleznev, V.; Pentin, I.; Vakhtomin, Y.; Smirnov, K.
Title 10.6 μm heterodyne receiver based on a superconducting hot-electron bolometer mixer and a quantum cascade laser Type Journal Article
Year 2019 Publication AIP Advances Abbreviated Journal AIP Advances
Volume 9 Issue 7 Pages 075307
Keywords (down) NbN HEB mixers, QCL, IR
Abstract We report on the development of a heterodyne receiver at mid-infrared wavelength for high-resolution spectroscopy applications. The receiver employs a superconducting NbN hot electron bolometer as a mixer and a room temperature distributed feedback quantum cascade laser operating at 10.6 μm (28.2 THz) as a local oscillator. The stabilization of the heterodyne receiver has been achieved using a feedback loop controlling the output power of the laser. Improved Allan variance times as well as a double sideband receiver noise temperature of 5000 K and a noise bandwidth of 2.8 GHz of the receiver system are demonstrated.

The work is supported in part by the National Key R&D Program of China under Grant 2018YFA0404701, by the CAS program under Grant QYZDJ-SSW-SLH043 and GJJSTD20180003, by the National Natural Science Foundation of China (NSFC) under Grant 11773083, by the “Hundred Talents Program” of the “Pioneer Initiative”, and in part by the CAS Key Lab for Radio Astronomy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2158-3226 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1293
Permanent link to this record
 

 
Author Semenov, A. D.; Gol’tsman, G. N.
Title Nonthermal mixing mechanism in a diffusion-cooled hot-electron detector Type Journal Article
Year 2000 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 87 Issue 1 Pages 502-510
Keywords (down) NbN HEB mixers, nonthermal
Abstract We present an analysis of a diffusion-cooled hot-electron detector fabricated from clean superconducting material with low transition temperature. The distinctive feature of a clean material, i.e., material with large electron mean free path, is a relatively weak inelastic electron scattering that is not sufficient for the establishment of an elevated thermodynamic electron temperature when the detector is subjected to irradiation. We propose an athermal model of a diffusion-cooled detector that relies on suppression of the superconducting energy gap by the actual dynamic distribution of excess quasiparticles. The resistive state of the device is caused by the electric field penetrating into the superconducting bridge from metal contacts. The dependence of the penetration length on the energy gap delivers the detection mechanism. The sources of the electric noise are equilibrium fluctuations of the number of thermal quasiparticles and frequency dependent shot noise. Using material parameters typical for A1, we evaluate performance of the device in the heterodyne regime at terahertz frequencies. Estimates show that the mixer may have a noise temperature of a few quantum limits and a bandwidth of a few tens of GHz, while the required local oscillator power is in the μW range due to ineffective suppression of the energy gap by quasiparticles with high energies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1558
Permanent link to this record
 

 
Author Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Gol'tsman, G.; Svechnikov, S.; Gershenzon, E.
Title Noise temperature and local oscillator power requirement of NbN phonon-cooled hot electron bolometric mixers at terahertz frequencies Type Journal Article
Year 1998 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.
Volume 73 Issue 19 Pages 2814-2816
Keywords (down) NbN HEB mixers, noise temperature, local oscillator power
Abstract In this letter, the noise performance of NbN-based phonon-cooled hot electron bolometric quasioptical mixers is investigated in the 0.55–1.1 THz frequency range. The best results of the double-sideband <cd><2018>DSB<cd><2019> noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz, and 1250 K at 1.1 THz. The water vapor in the signal path causes significant contribution to the measured receiver noise temperature around 1.1 THz. The devices are made from 3-nm-thick NbN film on high-resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are typically 0.2Ï«2 um. The amount of local oscillator power absorbed in the bolometer is less than 100 nW.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 911
Permanent link to this record
 

 
Author Zhang, W.; Li, N.; Jiang, L.; Ren, Y.; Yao, Q.-J.; Lin, Z.-H.; Shi, S.-C.; Voronov, B. M.; Gol’tsman, G. N.
Title Dependence of noise temperature of quasi-optical superconducting hot-electron bolometer mixers on bath temperature and optical-axis displacement Type Conference Article
Year 2008 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 6840 Issue Pages 684007 (1 to 8)
Keywords (down) NbN HEB mixers, noise temperature, LO power
Abstract It is known that the increase of bath temperature results in the decrease of critical current of superconducting hot-electron bolometer (HEB) mixers owing to the depression of superconductivity, thus leading to the degradation of the mixer’s sensitivity. Here we report our study on the effect of bath temperature on the heterodyne mixing performance of quasi-optical superconducting NbN HEB mixers incorporated with a two-arm log-spiral antenna. The correlation between the bath temperature, critical current, LO power requirement and noise temperature is investigated at 0.5 THz. Furthermore, the heterodyne mixing performance of quasi-optical superconducting NbN HEB mixers is examined while there is an optical-axis displacement between the center of the extended hemispherical silicon lens and the superconducting NbN HEB device, which is placed on the back of the lens. Detailed experimental results and analysis are presented.
Address
Corporate Author Thesis
Publisher Spie Place of Publication Editor Zhang, C.; Zhang, X.-C.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Terahertz Photonics
Notes Approved no
Call Number Serial 1415
Permanent link to this record
 

 
Author Chen, J.; Kang, L.; Jin, B. B.; Xu, W. W.; Wu, P. H.; Zhang, W.; Jiang, L.; Li, N.; Shi, S. C.; Gol'tsman, G. N.
Title Properties of terahertz superconducting hot electron bolometer mixers Type Journal Article
Year 2008 Publication Int. J. Terahertz Sci. Technol. Abbreviated Journal Int. J. Terahertz Sci. Technol.
Volume 1 Issue 1 Pages 37-41
Keywords (down) NbN HEB mixers, noise temperature
Abstract A quasi-optical superconducting niobium nitride (NbN) hot electron bolometer (HEB) mixer has been fabricated and measured in the terahertz (THz) frequency range of 0.5~2.52 THz. A receiver noise temperature of 2000 K at 2.52 THz has been obtained for the mixer without corrections. Also, the effect of a Parylene C anti-reflection (AR) coating on the silicon (Si) lens has been studied.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1417
Permanent link to this record
 

 
Author Jiang, L.; Antipov, S. V.; Voronov, B. M.; Gol'tsman, G. N.; Zhang, W.; Li, N.; Lin, Z. H.; Yao, Q. J.; Miao, W.; Shi, S. C.; Svechnikov, S. I.; Vakhtomin, Y. B.
Title Characterization of the performance of a quasi-optical NbN superconducting HEB mixer Type Journal Article
Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 17 Issue 2 Pages 395-398
Keywords (down) NbN HEB mixers, noise temperature
Abstract In this paper we focus mainly on the investigation of the performance of a quasi-optical (planar log-spiral antenna) phonon-cooled NbN superconducting hot electron bolometer (HEB) mixer, which is cryogenically cooled by a close-cycled 4-K cryocooler, at 500 and 850 GHz frequency bands. The mixer's noise performance, stability of IF output power, and local oscillator (LO) power requirement are characterized for three NbN superconducting HEB devices of different sizes. The transmission characteristics of Mylar and Zitex films with incidence waves of an elliptical polarization are also examined by measuring the mixer's noise temperature. The lowest receiver noise temperatures (with no corrections) of 750 and 1100 K are measured at 500 and 850 GHz, respectively. Experimental results also demonstrate that the bigger the HEB device is, the higher the stability of IF output power becomes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1051-8223 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1429
Permanent link to this record