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| Author | Finkel, M.; Thierschmann, H.; Galatro, L.; Katan, A. J.; Thoen, D. J.; de Visser, P. J.; Spirito, M.; Klapwijk, T. M. | ||||
| Title | Performance of THz components based on microstrip PECVD SiNx technology | Type | Journal Article | ||
| Year | 2017 | Publication | IEEE Trans. THz Sci. Technol. | Abbreviated Journal | IEEE Trans. THz Sci. Technol. |
| Volume | 7 | Issue | 6 | Pages | 765-771 |
| Keywords | transmission line measurements, power transmission lines, dielectrics, couplers, submillimeter wave circuits, coplanar waveguides, micromechanical devices | ||||
| Abstract | We present a performance analysis of passive THz components based on Microstrip transmission lines with a 2-μmthin plasma-enhanced chemical vapor deposition grown silicon nitride (PECVD SiNX) dielectric layer. A set of thru-reflect-line calibration structures is used for basic transmission line characterizations. We obtain losses of 9 dB/mm at 300 GHz. Branchline hybrid couplers are realized that exhibit 2.5-dB insertion loss, 1-dB amplitude imbalance, and -26-dB isolation, in agreement with simulations. We use the measured center frequency to determine the dielectric constant of the PECVD SiN x , which yields 5.9. We estimate the wafer-to-wafer variations to be of the order of 1%. Directional couplers are presented which exhibit -12-dB transmission to the coupled port and -26 dB to the isolated port. For transmission lines with 5-μm-thin silicon nitride (SiN x ), we observe losses below 4 dB/mm. The thin SiN x dielectric membrane makes the THz components compatible with scanning probe microscopy cantilevers allowing the application of this technology in on-chip circuits of a THz near-field microscope. | ||||
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| ISSN | 2156-342X | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1294 | |||
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| 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 | 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. | ||||
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| ISSN | 1051-8223 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1296 | |||
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| Author | Korneeva, Y. P.; Vodolazov, D. Y.; Semenov, A. V.; Florya, I. N.; Simonov, N.; Baeva, E.; Korneev, A. A.; Goltsman, G. N.; Klapwijk, T. M. | ||||
| Title | Optical single-photon detection in micrometer-scale NbN bridges | Type | Journal Article | ||
| Year | 2018 | Publication | Phys. Rev. Applied | Abbreviated Journal | Phys. Rev. Applied |
| Volume | 9 | Issue | 6 | Pages | 064037 (1 to 13) |
| Keywords | NbN SSPD, SNSPD | ||||
| Abstract | We demonstrate experimentally that single-photon detection can be achieved in micrometer-wide NbN bridges, with widths ranging from 0.53 to 5.15 μm and for photon wavelengths of 408 to 1550 nm. The microbridges are biased with a dc current close to the experimental critical current, which is estimated to be about 50% of the theoretically expected depairing current. These results offer an alternative to the standard superconducting single-photon detectors, based on nanometer-scale nanowires implemented in a long meandering structure. The results are consistent with improved theoretical modeling based on the theory of nonequilibrium superconductivity, including the vortex-assisted mechanism of initial dissipation. | ||||
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| ISSN | 2331-7019 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1303 | |||
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| Author | Korneev, A.; Korneeva, Y.; Florya, I.; Semenov, A.; Goltsman, G. | ||||
| Title | Photon switching statistics in multistrip superconducting single-photon detectors | Type | Journal Article | ||
| Year | 2018 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 28 | Issue | 7 | Pages | 1-4 |
| Keywords | SSPD, SNSPD | ||||
| Abstract | We study photon count statistics in superconducting single-photon detectors consisting of up to 70 narrow superconducting strips connected in parallel. Using interarrival time analysis, we demonstrate that our samples are operated in the “arm-trigger” regime and require up to seven subsequently absorbed photons to form a resistive state in the whole sample. We also performed numerical simulation of the light and dark count rates versus detector bias current, which are in good agreement with the experimental results. | ||||
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| ISSN | 1051-8223 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1304 | |||
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| Author | Sidorova, M. V.; Kozorezov, A. G.; Semenov, A. V.; Korneeva, Y. P.; Mikhailov, M. Y.; Devizenko, A. Y.; Korneev, A. A.; Chulkova, G. M.; Goltsman, G. N. | ||||
| Title | Nonbolometric bottleneck in electron-phonon relaxation in ultrathin WSi films | Type | Journal Article | ||
| Year | 2018 | Publication | Phys. Rev. B | Abbreviated Journal | Phys. Rev. B |
| Volume | 97 | Issue | 18 | Pages | 184512 (1 to 13) |
| Keywords | WSi films, diffusion constant, SSPD, SNSPD | ||||
| Abstract | We developed the model of the internal phonon bottleneck to describe the energy exchange between the acoustically soft ultrathin metal film and acoustically rigid substrate. Discriminating phonons in the film into two groups, escaping and nonescaping, we show that electrons and nonescaping phonons may form a unified subsystem, which is cooled down only due to interactions with escaping phonons, either due to direct phonon conversion or indirect sequential interaction with an electronic system. Using an amplitude-modulated absorption of the sub-THz radiation technique, we studied electron-phonon relaxation in ultrathin disordered films of tungsten silicide. We found an experimental proof of the internal phonon bottleneck. The experiment and simulation based on the proposed model agree well, resulting in τe−ph∼140–190 ps at TC=3.4K, supporting the results of earlier measurements by independent techniques. | ||||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1305 | |||
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| Author | Tretyakov, I. V.; Anfertyev, V. A.; Revin, L. S.; Kaurova, N. S.; Voronov, B. M.; Vaks, V. L.; Goltsman, G. N. | ||||
| Title | Sensitivity and resolution of a heterodyne receiver based on the NbN HEB mixer with a quantum-cascade laser as a local oscillator | Type | Journal Article | ||
| Year | 2018 | Publication | Radiophys. Quant. Electron. | Abbreviated Journal | Radiophys. Quant. Electron. |
| Volume | 60 | Issue | 12 | Pages | 988-992 |
| Keywords | NbN HEB mixer | ||||
| Abstract | We present the results of experimental studies of the basic characteristics and operation features of a terahertz heterodyne detector based on the superconducting NbN HEB mixer and a quantum cascade laser as a local oscillator operating at a frequency of 2.02 THz. The measured noise temperature of such a mixer amounted to 1500 K. The spectral resolution of the detector is determined by the width of the local-oscillator spectral line whose measured value does not exceed 1 MHz. The quantum-cascade laser could be linearly tuned with respect to frequency with the coefficient 7.2 MHz/mA within the limits of the current oscillation bandwidth. | ||||
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| ISSN | 0033-8443 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1307 | |||
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| Author | Bandurin, D. A.; Gayduchenko, I.; Cao, Y.; Moskotin, M.; Principi, A.; Grigorieva, I. V.; Goltsman, G.; Fedorov, G.; Svintsov, D. | ||||
| Title | Dual origin of room temperature sub-terahertz photoresponse in graphene field effect transistors | Type | Journal Article | ||
| Year | 2018 | Publication | Appl. Phys. Lett. | Abbreviated Journal | Appl. Phys. Lett. |
| Volume | 112 | Issue | 14 | Pages | 141101 (1 to 5) |
| Keywords | graphene field effect transistors, FET | ||||
| Abstract | Graphene is considered as a promising platform for detectors of high-frequency radiation up to the terahertz (THz) range due to its superior electron mobility. Previously, it has been shown that graphene field effect transistors (FETs) exhibit room temperature broadband photoresponse to incoming THz radiation, thanks to the thermoelectric and/or plasma wave rectification. Both effects exhibit similar functional dependences on the gate voltage, and therefore, it was difficult to disentangle these contributions in previous studies. In this letter, we report on combined experimental and theoretical studies of sub-THz response in graphene field-effect transistors analyzed at different temperatures. This temperature-dependent study allowed us to reveal the role of the photo-thermoelectric effect, p-n junction rectification, and plasmonic rectification in the sub-THz photoresponse of graphene FETs. D.A.B. acknowledges the Leverhulme Trust for financial support. The work of D.S. was supported by Grant No. 16-19-10557 of the Russian Scientific Foundation (theoretical model). G.F., I.G., M.M., and G.G. acknowledge the Russian Science Foundation [Grant No. 14-19-01308 (MIET, cryostat upgrade) and Grant No. 17-72-30036, (MSPU, photoresponse measurements), the Ministry of Education and Science of the Russian Federation (Contract No. 14.B25.31.0007 (device fabrication) and Task No. 3.7328.2017/LS (NEP analyses)] and the Russian Foundation for Basic Research [Grant No. 15-02-07841 (device design)]. The authors are grateful to Professor M. S. Shur for helpful discussions. |
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| ISSN | 0003-6951 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1309 | |||
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| Author | Florya, I. N.; Korneeva, Y. P.; Mikhailov, M. Y.; Devizenko, A. Y.; Korneev, A. A.; Goltsman, G. N. | ||||
| Title | Photon counting statistics of superconducting single-photon detectors made of a three-layer WSi film | Type | Journal Article | ||
| Year | 2018 | Publication | Low Temp. Phys. | Abbreviated Journal | Low Temp. Phys. |
| Volume | 44 | Issue | 3 | Pages | 221-225 |
| Keywords | WSi SSPD, SNSPD | ||||
| Abstract | Superconducting nanowire single-photon detectors (SNSPD) are used in quantum optics when record-breaking time resolution, high speed, and exceptionally low levels of dark counts (false readings) are required. Their detection efficiency is limited, however, by the absorption coefficient of the ultrathin superconducting film for the detected radiation. One possible way of increasing the detector absorption without limiting its broadband response is to make a detector in the form of several vertically stacked layers and connect them in parallel. For the first time we have studied single-photon detection in a multilayer structure consisting of three superconducting layers of amorphous tungsten silicide (WSi) separated by thin layers of amorphous silicon. Two operating modes of the detector are illustrated: an avalanche regime and an arm-trigger regime. A shift in these modes occurs at currents of ∼0.5–0.6 times the critical current of the detector. This work was supported by technical task No. 88 for scientific research at the National Research University “Higher School of Economics,” Grant No. 14.V25.31.0007 from the Ministry of Education and Science of Russia, and the work of G. N. Goltsman was supported by task No. 3.7328.2017/VU of the Ministry of Education and Science of Russia. |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1063-777X | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1310 | |||
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| Author | Iomdina, E. N.; Seliverstov, S. V.; Sianosyan, A. A.; Teplyakova, K. O.; Rusova, A. A.; Goltsman, G. N. | ||||
| Title | Terahertz scanning for evaluation of corneal and scleral hydration | Type | Journal Article | ||
| Year | 2018 | Publication | Sovremennye tehnologii v medicine | Abbreviated Journal | STM |
| Volume | 10 | Issue | 4 | Pages | 143-149 |
| Keywords | BWO; Golay cell; medicine; cornea; sclera; THz radiation; corneal hydration; backward-wave oscillator; avalanche transit-time diode; IMPATT diode | ||||
| Abstract | The aim of the investigation was to study the prospects of using continuous THz scanning of the cornea and the sclera to determine water concentration in these tissues and on the basis of the obtained data to develop the experimental installation for monitoring corneal and scleral hydration degree.Materials and Methods. To evaluate corneal and scleral transmittance and reflectance spectra in the THz range, the developed experimental installations were used to study 3 rabbit corneas and 3 scleras, 2 whole rabbit eyes, and 3 human scleras. Besides, two rabbit eyes were studied in vivo prior to keratorefractive surgery as well as 10 and 21 days following the surgery (LASIK).Results. There have been created novel experimental installations enabling in vitro evaluation of frequency dependence of corneal and scleral transmittance coefficients and reflectance coefficients on water percentage in the THz range. Decrease in corneal water content by 1% was found to lead to reliably established decrease in the reflected signal by 13%. The reflectance spectrum of the whole rabbit eye was measured in the range of 0.13–0.32 THz. The study revealed the differences between the indices of rabbit cornea and sclera, as well as rabbit and human sclera. There was developed a laboratory model of the installation for in vivo evaluation of corneal and scleral hydration using THz radiation.Conclusion. The preliminary findings show that the proposed technique based on the use of continuous THz radiation can be employed to create a device for noninvasive control of corneal and scleral hydration. | ||||
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Approved | no | |||
| Call Number | Serial | 1315 | |||
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| Author | Fedorov, G.; Gayduchenko, I.; Titova, N.; Gazaliev, A.; Moskotin, M.; Kaurova, N.; Voronov, B.; Goltsman, G. | ||||
| Title | Carbon nanotube based schottky diodes as uncooled terahertz radiation detectors | Type | Journal Article | ||
| Year | 2018 | Publication | Phys. Status Solidi B | Abbreviated Journal | Phys. Status Solidi B |
| Volume | 255 | Issue | 1 | Pages | 1700227 (1 to 6) |
| Keywords | carbon nanotube schottky diodes, CNT | ||||
| Abstract | Despite the intensive development of the terahertz technologies in the last decade, there is still a shortage of efficient room‐temperature radiation detectors. Carbon nanotubes (CNTs) are considered as a very promising material possessing many of the features peculiar for graphene (suppression of backscattering, high mobility, etc.) combined with a bandgap in the carrier spectrum. In this paper, we investigate the possibility to incorporate individual CNTs into devices that are similar to Schottky diodes. The latter is currently used to detect radiation with a frequency up to 50 GHz. We report results obtained with semiconducting (bandgap of about 0.5 eV) and quasi‐metallic (bandgap of few meV) single‐walled carbon nanotubes (SWNTs). Semiconducting CNTs show better performance up to 300 GHz with responsivity up to 100 V W−1, while quasi‐metallic CNTs are shown to operate up to 2.5 THz. | ||||
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| ISSN | 0370-1972 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1321 | |||
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| Author | Seliverstov, S. V.; Anfertyev, V. A.; Tretyakov, I. V.; Ozheredov, I. A.; Solyankin, P. M.; Revin, L. S.; Vaks, V. L.; Rusova, A. A.; Goltsman, G. N.; Shkurinov, A. P. | ||||
| Title | Terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser | Type | Journal Article | ||
| Year | 2017 | Publication | Radiophys. Quant. Electron. | Abbreviated Journal | Radiophys. Quant. Electron. |
| Volume | 60 | Issue | 7 | Pages | 518-524 |
| Keywords | NbN HEB mixer, QCL | ||||
| Abstract | We study characteristics of the laboratory prototype of a terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. The results obtained demonstrate the possibility to use this receiver as a basis for creation of a high-sensitivity terahertz spectrometer, which can be used in many basic and practical applications. A significant advantage of this receiver will be the possibility of placing the mixer and heterodyne in the same cryostat, which will reduce the device dimensions considerably. The obtained experimental results are analyzed, and methods of optimizing the parameters of the receiver are proposed. | ||||
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| ISSN | 0033-8443 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1322 | |||
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| Author | Trifonov, A.; Tong, C.-Y. E.; Grimes, P.; Lobanov, Y.; Kaurova, N.; Blundell, R.; Goltsman, G. | ||||
| Title | Development of a silicon membrane-based multipixel hot electron bolometer receiver | Type | Journal Article | ||
| Year | 2017 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 27 | Issue | 4 | Pages | 1-5 |
| Keywords | Multi-pixel, NbN HEB, silicon-on-insulator, horn array | ||||
| Abstract | We report on the development of a multipixel hot electron bolometer (HEB) receiver fabricated using silicon membrane technology. The receiver comprises a 2 × 2 array of four HEB mixers, fabricated on a single chip. The HEB mixer chip is based on a superconducting NbN thin-film deposited on top of the silicon-on-insulator (SOI) substrate. The thicknesses of the device layer and handling layer of the SOI substrate are 20 and 300 μm, respectively. The thickness of the device layer is chosen such that it corresponds to a quarter-wave in silicon at 1.35 THz. The HEB mixer is integrated with a bow-tie antenna structure, in turn designed for coupling to a circular waveguide, fed by a monolithic drilled smooth-walled horn array. | ||||
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| ISSN | 1051-8223 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1324 | |||
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| Author | Korneeva, Y.; Florya, I.; Vdovichev, S.; Moshkova, M.; Simonov, N.; Kaurova, N.; Korneev, A.; Goltsman, G. | ||||
| Title | Comparison of hot spot formation in nbn and mon thin superconducting films after photon absorption | Type | Journal Article | ||
| Year | 2017 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 27 | Issue | 4 | Pages | 1-4 |
| Keywords | MoNx SSPD | ||||
| Abstract | In superconducting single-photon detectors (SSPD), the efficiency of local suppression of superconductivity and hotspot formation is controlled by diffusivity and electron-phonon interaction time. Here, we selected a material, 3.6-nm-thick MoNx film, which features diffusivity close to those of NbN traditionally used for SSPD fabrication, but with electron-phonon interaction time an order of magnitude larger. In MoN ∞ detectors, we study the dependence of detection efficiency on bias current, photon energy, and strip width, and compare it with NbN SSPD. We observe nonlinear current-energy dependence in MoNx SSPD and more pronounced plateaus in dependences of detection efficiency on bias current, which we attribute to longer electron-phonon interaction time. | ||||
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| ISSN | 1051-8223 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1325 | |||
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| Author | Krause, S.; Mityashkin, V.; Antipov, S.; Gol’tsman, G.; Meledin, D.; Desmaris, V.; Belitsky, V.; Rudziński, M. | ||||
| Title | Reduction of phonon escape time for nbn hot electron bolometers by using gan buffer layers | Type | Journal Article | ||
| Year | 2017 | Publication | IEEE Trans. Terahertz Sci. Technol. | Abbreviated Journal | IEEE Trans. Terahertz Sci. Technol. |
| Volume | 7 | Issue | 1 | Pages | 53-59 |
| Keywords | NbN HEB mixer | ||||
| Abstract | In this paper, we investigated the influence of the GaN buffer layer on the phonon escape time of phonon-cooled hot electron bolometers (HEBs) based on NbN material and compared our findings to conventionally employed Si substrate. The presented experimental setup and operation of the HEB close to the critical temperature of the NbN film allowed for the extraction of phonon escape time in a simplified manner. Two independent experiments were performed at GARD/Chalmers and MSPU on a similar experimental setup at frequencies of approximately 180 and 140 GHz, respectively, and have shown reproducible and consistent results. By fitting the normalized IF measurement data to the heat balance equations, the escape time as a fitting parameter has been deduced and amounts to 45 ps for the HEB based on Si substrate as in contrast to a significantly reduced escape time of 18 ps for the HEB utilizing the GaN buffer layer under the assumption that no additional electron diffusion has taken place. This study indicates a high phonon transmissivity of the NbN-to-GaN interface and a prospective increase of IF bandwidth for HEB made of NbN on GaN buffer layers, which is desirable for future THz HEB heterodyne receivers. | ||||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 2156-3446 | ISBN | Medium | ||
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Approved | no | |||
| Call Number | Serial | 1330 | |||
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| Author | Trifonov, A.; Tong, C.-Y. E.; Lobanov, Y.; Kaurova, N.; Blundell, R.; Goltsman, G. | ||||
| Title | Photon absorption near the gap frequency in a hot electron bolometer | Type | Journal Article | ||
| Year | 2017 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 27 | Issue | 4 | Pages | 1-4 |
| Keywords | NBN HEB mixer | ||||
| Abstract | The superconducting energy gap is a fundamental characteristic of a superconducting film, which, together with the applied pump power and the biasing setup, defines the instantaneous resistive state of the Hot Electron Bolometer (HEB) mixer at any given bias point on the I-V curve. In this paper we report on a series of experiments, in which we subjected the HEB to radiation over a wide frequency range along with parallel microwave injection. We have observed three distinct regimes of operation of the HEB, depending on whether the radiation is above the gap frequency, far below it or close to it. These regimes are driven by the different patterns of photon absorption. The experiments have allowed us to derive the approximate gap frequency of the device under test as about 585 GHz. Microwave injection was used to probe the HEB impedance. Spontaneous switching between the superconducting (low resistive) state and a quasi-normal (high resistive) state was observed. The switching pattern depends on the particular regime of HEB operation and can assume a random pattern at pump frequencies below the gap to a regular relaxation oscillation running at a few MHz when pumped above the gap. | ||||
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| ISSN | 1558-2515 | ISBN | Medium | ||
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| Notes |
Approved | no | |||
| Call Number | Serial | 1331 | |||
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