|   | 
Details
   web
Records
Author Gershenzon, E. M.; Gol’tsman, G. N.; Dzardanov, A. L.; Zorin, M. A.
Title Ultrafast superconductive switch Type Journal Article
Year 1991 Publication IEEE Trans. Magn. Abbreviated Journal IEEE Trans. Magn.
Volume (down) 27 Issue 2 Pages 2844-2846
Keywords Nb superconducting switch
Abstract The transition from superconductive to resistive state caused by infrared radiation and bias current pulses was investigated in order to minimize switching time tau and driving power W. Experimental results for Nb microstrips confirm the correctness of calculations based on the model of electron heating. For Nb switches, tau measured directly is 0.3-0.8 ns for radiation pulses and 1-3 ns for bias current pulses at T=4.2 K, while for YBaCuO switches at T=77 K it is expected to be several picoseconds. For an YBaCuO sample with the dimensions of 5*2*0.15 mu m/sup 2/, W was 10 mW, and it can be further reduced to the order of several microwatts by decreasing the volume of the sample.
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 1941-0069 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1680
Permanent link to this record
 

 
Author Shangina, E. L.; Smirnov, K. V.; Morozov, D. V.; Kovalyuk, V. V.; Goltsman, G. N.; Verevkin, A. A.; Toropov, A. I.; Mauskopf, P.
Title Concentration dependence of energy relaxation time in AlGaAs/GaAs heterojunctions: direct measurements Type Journal Article
Year 2011 Publication Semicond. Sci. Technol. Abbreviated Journal Semicond. Sci. Technol.
Volume (down) 26 Issue 2 Pages 025013
Keywords AlGaAs/GaAs heterojunctions
Abstract We present measurements of the energy relaxation time, τε, of electrons in a single heterojunction in a quasi-equilibrium state using microwave time-resolved spectroscopy at 4.2 K. We find the relaxation time has a power-law dependence on the carrier density of the two-dimensional electron gas, τε∝nγs with γ = 0.40 ± 0.02 for values of the carrier density, ns, from 1.6 × 1011 to 6.6 × 1011cm−2. The results are in good agreement with predictions taking into account the scattering of the carriers by both piezoelectric and deformation potential acoustic phonons. We compare these results with indirect measurements of the energy relaxation time from energy loss measurements involving Joule heating of the electron gas.
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 0268-1242 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1215
Permanent link to this record
 

 
Author Iomdina, E. N.; Seliverstov, S. V.; Teplyakova, K. O.; Jani, E. V.; Pozdniakova, V. V.; Polyakova, O. N.; Goltsman, G. N.
Title Terahertz scanning of the rabbit cornea with experimental UVB-induced damage: in vivo assessment of hydration and its verification Type Journal Article
Year 2021 Publication J. Biomed. Opt. Abbreviated Journal J. Biomed. Opt.
Volume (down) 26 Issue 4 Pages
Keywords medicine; scheimpflug imaging; UVB; confocal microscopy; cornea; optical coherent tomography; rabbit eyes; terahertz radiation
Abstract SIGNIFICANCE: Water content plays a vital role in the normally functioning visual system; even a minor disruption in the water balance may be harmful. Today, no direct method exists for corneal hydration assessment, while it could be instrumental in early diagnosis and control of a variety of eye diseases. The use of terahertz (THz) radiation, which is highly sensitive to water content, appears to be very promising. AIM: To find out how THz scanning parameters of corneal tissue measured by an experimental setup, specially developed for in vivo contactless estimations of corneal reflectivity coefficient (RC), are related to pathological changes in the cornea caused by B-band ultraviolet (UVB) exposure. APPROACH: The setup was tested on rabbit eyes in vivo. Prior to the course of UVB irradiation and 1, 5, and 30 days after it, a series of examinations of the corneal state was made. At the same time points, corneal hydration was assessed by measuring RC. RESULTS: The obtained data confirmed the negative impact of UVB irradiation course on the intensity of tear production and on the corneal thickness and optical parameters. A significant (1.8 times) increase in RC on the 5th day after the irradiation course, followed by a slight decrease on the 30th day after it was revealed. The RC increase measured 5 days after the UVB irradiation course generally corresponded to the increase (by a factor of 1.3) of tear production. RC increase occurred with the corneal edema, which was manifested by corneal thickening (by 18.2% in the middle area and 17.6% in corneal periphery) and an increased volume of corneal tissue (by 17.6%). CONCLUSIONS: Our results demonstrate that the proposed approach can be used for in vivo contactless estimation of the reflectivity of rabbit cornea in the THz range and, thereby, of cornea hydration.
Address National Research University Higher School of Economics, Moscow Institute of Electronics and Mathema, Russia
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1083-3668 ISBN Medium
Area Expedition Conference
Notes PMID:33834684; PMCID:PMC8027227 Approved no
Call Number Serial 1258
Permanent link to this record
 

 
Author Korneeva, Y.; Sidorova, M.; Semenov, A.; Krasnosvobodtsev, S.; Mitsen, K.; Korneev, A.; Chulkova, G.; Goltsman, G.
Title Comparison of hot-spot formation in NbC and NbN single-photon detectors Type Journal Article
Year 2016 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 26 Issue 3 Pages 1-4
Keywords NbC, NbN SSPD, SNSPD
Abstract We report an experimental investigation of the hot-spot evolution in superconducting single-photon detectors made of disordered superconducting materials with different diffusivity and energy downconversion time values, i.e., 33-nm-thick NbN and 23-nm-thick NbC films. We have demonstrated that, in NbC film, only 405-nm photons produce sufficiently large hot spot to trigger a single-photon response. The dependence of detection efficiency on bias current for 405-nm photons in NbC is similar to that for 3400-nm photons in NbN. In NbC, large diffusivity and downconversion time result in 1-D critical current suppression profile compared with the usual 2-D profile in NbN.
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 1348
Permanent link to this record
 

 
Author Gershenzon, E. M.; Gol'tsman, G. N.; Semenov, A. D.
Title Submillimeter backward wave tube spectrometer for measuring superconducting film transmission Type Journal Article
Year 1983 Publication Pribory i Tekhnika Eksperimenta Abbreviated Journal Pribory i Tekhnika Eksperimenta
Volume (down) 26 Issue 5 Pages 134-137
Keywords BWO spectroscopy, spectrometer, transmission
Abstract A spectrometer employing six backward wave tubes is described. It is intended for investigation of superconductors in the 0.2-3 mm range of wave lengths. During the measurement of the transmission spectrum it is possible to determine the energy gap for superconduct1ng films 50 to 4000 A thick. The transmission factor can vary from 10-1 to 10-9. Spectrum of relation of film transmission factors in superconducting and normal states is measured for determining the energy gap 2 Δ. The transmission spectrum obtained by means of a computer for vanadium film 300 A thick is given as an example. The energy gap 2 Δ = 1.4 MeV
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Russian Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0032-8162 ISBN Medium
Area Expedition Conference
Notes Субмиллиметровый спектрометр с лампами обратной волны для измерения пропускания сверхпроводниковых пленок Approved no
Call Number Serial 1713
Permanent link to this record
 

 
Author Ferrari, S.; Kovalyuk, V.; Hartmann, W.; Vetter, A.; Kahl, O.; Lee, C.; Korneev, A.; Rockstuhl, C.; Gol'tsman, G.; Pernice, W.
Title Hot-spot relaxation time current dependence in niobium nitride waveguide-integrated superconducting nanowire single-photon detectors Type Journal Article
Year 2017 Publication Opt. Express Abbreviated Journal Opt. Express
Volume (down) 25 Issue 8 Pages 8739-8750
Keywords SSPD, SNSPD, photon counting; Infrared; Quantum detectors; Integrated optics; Multiphoton processes; Photon statistics
Abstract We investigate how the bias current affects the hot-spot relaxation dynamics in niobium nitride. We use for this purpose a near-infrared pump-probe technique on a waveguide-integrated superconducting nanowire single-photon detector driven in the two-photon regime. We observe a strong increase in the picosecond relaxation time for higher bias currents. A minimum relaxation time of (22 +/- 1)ps is obtained when applying a bias current of 50% of the switching current at 1.7 K bath temperature. We also propose a practical approach to accurately estimate the photon detection regimes based on the reconstruction of the measured detector tomography at different bias currents and for different illumination conditions.
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 RPLAB @ kovalyuk @ Serial 1118
Permanent link to this record
 

 
Author Tikhonov, V. V.; Boyarskii, D. A.; Polyakova, O. N.; Dzardanov, A. L.; Goltsman, G. N.
Title Radiophysical and dielectric properties of ore minerals in 12--145 GHz frequency range Type Journal Article
Year 2010 Publication PIER B Abbreviated Journal PIER B
Volume (down) 25 Issue Pages 349-367
Keywords complex permittivity, ore minerals
Abstract The paper discusses a retrieval technique of complex permittivity of ore minerals in frequency ranges of 12--38 GHz and 77--145 GHz. The method is based on measuring frequency dependencies of transmissivity and reflectivity of plate-parallel mineral samples. In the 12--38 GHz range, the measurements were conducted using a panoramic standing wave ratio and attenuation meter. In the 77--145 GHz range, frequency dependencies of transmissivity and reflectivity were obtained using millimeter-band spectrometer with backward-wave oscillators. The real and imaginary parts of complex permittivity of a mineral were determined solving an equation system for frequency dependencies of transmissivity and reflectivity of an absorbing layer located between two dielectric media. In the course of the work, minerals that are primary ores in iron, zinc, copper and titanium mining were investigated: magnetite, hematite, sphalerite, chalcopyrite, pyrite, and ilmenite.
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 RPLAB @ gujma @ Serial 639
Permanent link to this record
 

 
Author Trifonov, A.; Tong, C.-Y. E.; Blundell, R.; Ryabchun, S.; Gol'tsman, G.
Title Probing the stability of HEB mixers with microwave injection Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 25 Issue 3 Pages 2300404 (1 to 4)
Keywords NbN HEB mixer, stability, Allan-variance
Abstract Using a microwave probe as a tool, we have performed experiments aimed at understanding the origin of the output-power fluctuations in hot-electron-bolometer (HEB) mixers. We use a probe frequency of 1.5 GHz. The microwave probe picks up impedance changes of the HEB, which are examined upon demodulation of the reflected wave outside the cryostat. This study shows that the HEB mixer operates in two different regimes under a terahertz pump. At a low pumping level, strong pulse modulation is observed, as the device switches between the superconducting state and the normal state at a rate of a few megahertz. When pumped much harder, to approximate the low-noise mixer operating point, residual modulation can still be observed, showing that the HEB mixer is intrinsically unstable even in the resistive state. Based on these observations, we introduced a low-frequency termination to the HEB mixer. By terminating the device in a 50-Ω resistor in the megahertz frequency range, we have been able to improve the output-power Allan time of our HEB receiver by a factor of four to about 10 s for a detection bandwidth of 15 MHz, with a corresponding gain fluctuation of about 0.035%.
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 1355
Permanent link to this record
 

 
Author Lobanov, Y.; Shcherbatenko, M.; Finkel, M.; Maslennikov, S.; Semenov, A.; Voronov, B. M.; Rodin, A. V.; Klapwijk, T. M.; Gol'tsman, G. N.
Title NbN hot-electron-bolometer mixer for operation in the near-IR frequency range Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 25 Issue 3 Pages 2300704 (1 to 4)
Keywords HEB mixer, IR, optical antenna
Abstract Traditionally, hot-electron-bolometer (HEB) mixers are employed for THz and “super-THz” heterodyne detection. To explore the near-IR spectral range, we propose a fiber-coupled NbN film based HEB mixer. To enhance the incident-light absorption, a quasi-antenna consisting of a set of parallel stripes of gold is used. To study the antenna effect on the mixer performance, we have experimentally studied a set of devices with different size of the Au stripe and spacing between the neighboring stripes. With use of the well-known isotherm technique we have estimated the absorption efficiency of the mixer, and the maximum efficiency has been observed for devices with the smallest pitch of the alternating NbN and NbN-Au stripes. Also, a proper alignment of the incident Eâƒ<2014>-field with respect to the stripes allows us to improve the coupling further. Studying IV-characteristics of the mixer under differently-aligned Eâƒ<2014>-field of the incident radiation, we have noticed a difference in their shape. This observation suggests that a difference exists in the way the two waves with orthogonal polarizations parallel and perpendicular Eâƒ<2014>-field to the stripes heat the electrons in the HEB mixer. The latter results in a variation in the electron temperature distribution over the HEB device irradiated by the two waves.
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 952
Permanent link to this record
 

 
Author Seliverstov, S.; Maslennikov, S.; Ryabchun, S.; Finkel, M.; Klapwijk, T. M.; Kaurova, N.; Vachtomin, Yu.; Smirnov, K.; Voronov, B.; Goltsman, G.
Title Fast and sensitive terahertz direct detector based on superconducting antenna-coupled hot electron bolometer Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 25 Issue 3 Pages 2300304
Keywords HEB detector responsivity, HEB model, numerical calculations, numerical model
Abstract We characterize superconducting antenna-coupled hot-electron bolometers for direct detection of terahertz radiation operating at a temperature of 9.0 K. The estimated value of responsivity obtained from lumped-element theory is strongly different from the measured one. A numerical calculation of the detector responsivity is developed, using the Euler method, applied to the system of heat balance equations written in recurrent form. This distributed element model takes into account the effect of nonuniform heating of the detector along its length and provides results that are in better agreement with the experiment. At a signal frequency of 2.5 THz, the measured value of the optical detector noise equivalent power is 2.0 × 10-13 W · Hz-0.5. The value of the bolometer time constant is 35 ps. The corresponding energy resolution is about 3 aJ. This detector has a sensitivity similar to that of the state-of-the-art sub-millimeter detectors operating at accessible cryogenic temperatures, but with a response time several orders of magnitude shorter.
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 953
Permanent link to this record
 

 
Author Korneev, A. A.; Korneeva, Y. P.; Mikhailov, M. Yu.; Pershin, Y. P.; Semenov, A. V.; Vodolazov, D. Yu.; Divochiy, A. V.; Vakhtomin, Y. B.; Smirnov, K. V.; Sivakov, A. G.; Devizenko, A. Yu.; Goltsman, G. N.
Title Characterization of MoSi superconducting single-photon detectors in the magnetic field Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 25 Issue 3 Pages 2200504 (1 to 4)
Keywords SSPD, SNSPD
Abstract We investigate the response mechanism of nanowire superconducting single-photon detectors (SSPDs) made of amorphous MoxSi1-x. We study the dependence of photon count and dark count rates on bias current in magnetic fields up to 113 mT at 1.7 K temperature. The observed behavior of photon counts is similar to the one recently observed in NbN SSPDs. Our results show that the detecting mechanism of relatively high-energy photons does not involve the vortex penetration from the edges of the film, and on the contrary, the detecting mechanism of low-energy photons probably involves the vortex penetration from the film edges.
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 RPLAB @ akorneev @ KorneevIEEE2015 Serial 991
Permanent link to this record
 

 
Author Kardakova, A. I.; Coumou, P. C. J. J.; Finkel, M. I.; Morozov, D. V.; An, P. P.; Goltsman, G. N.; Klapwijk, T. M.
Title Electron–phonon energy relaxation time in thin strongly disordered titanium nitride films Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 25 Issue 3 Pages 1-4
Keywords TiN MKID
Abstract We have measured the energy relaxation times from the electron bath to the phonon bath in strongly disordered TiN films grown by atomic layer deposition. The measured values of τ eph vary from 12 to 91 ns. Over a temperature range from 3.4 to 1.7 K, they follow T -3 temperature dependence, which are consistent with values of τ eph reported previously for sputtered TiN films. For the most disordered film, with an effective elastic mean free path of 0.35 nm, we find a faster relaxation and a stronger temperature dependence, which may be an additional indication of the influence of strong disorder on a superconductor.
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 1296
Permanent link to this record
 

 
Author Tong, C.-Y. E.; Trifonov, A.; Shurakov, A.; Blundell, R.; Gol’tsman, G.
Title A microwave-operated hot-electron-bolometric power detector for terahertz radiation Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume (down) 25 Issue 3 Pages 2300604 (1 to 4)
Keywords NbN HEB mixer
Abstract A new class of microwave-operated THz power detectors based on the NbN hot-electron-bolometer (HEB) mixer is proposed. The injected microwave signal ( 1 GHz) serves the dual purpose of pumping the HEB element and enabling the read-out of the internal state of the device. A cryogenic amplifier amplifies the reflected microwave signal from the device and a homodyne scheme recovers the effects of the incident THz radiation. Two modes of operation have been identified, depending on the level of incident radiation. For weak signals, we use a chopper to chop the incident radiation against a black body reference and a lock-in amplifier to perform synchronous detection of the homodyne readout. The voltage measured is proportional to the incident power, and we estimate an optical noise equivalent power of  5pW/ √Hz at 0.83 THz. At higher signal levels, the homodyne circuit recovers the stream of steady relaxation oscillation pulses from the HEB device. The frequency of these pulses is in the MHz frequency range and bears a linear relationship with the incident THz radiation over an input power range of  15 dB. A digital frequency counter is used to measure THz power. The applicable power range is between 1 nW and 1 μW.
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 1558-2515 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1354
Permanent link to this record
 

 
Author Gershenzon, E.M.; Gol'tsman, G.N.; Ptitsyna, N. G.
Title Carrier lifetime in excited states of shallow impurities in germanium Type Journal Article
Year 1977 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume (down) 25 Issue 12 Pages 539-543
Keywords Ge, shallow impurities, excited states
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1726
Permanent link to this record
 

 
Author Гершензон, Е. М.; Грачев, С. А.; Литвак-Горская, Л. Б.
Title Механизм преобразования частоты в n-InSb-смесителе Type Journal Article
Year 1991 Publication Физика и техника полупроводников Abbreviated Journal Физика и техника полупроводников
Volume (down) 25 Issue 11 Pages 1986-1998
Keywords n-InSb mixer
Abstract Проведено комплексное исследование n-InSb смесителя на λ=2.6 мм, включающее в себя исследование вольт-амперных характеристик при E=0−2 В/см, температурной зависимости проводимости в диапазоне T=1.6−20 K, высокочастотной проводимости при f=0.5−10 МГц и магнитосопротивления при H=0−5 кЭ. Показано, что в оптимальном режиме механизм преобразования частоты связан с фотоионизационными процессами при прыжковой фотопроводимости (ПФП). На основе модели ПФП рассчитан коэффициент преобразования смесителя и произведено сопоставление его с экспериментом. Показана несостоятельность модели преобразования частоты в компенсированном n-InSb (K≥0.8), основанной на разогреве электронов. Обсуждены требования к параметрам материала и режимам n-InSb смесителя миллиметрового диапазона волн.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Russian 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 1753
Permanent link to this record