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| Author | Seliverstov, Sergey V.; Rusova, Anastasia A.; Kaurova, Natalya S.; Voronov, Boris M.; Goltsman, Gregory N. | ||||
| Title | AC-biased superconducting NbN hot-electron bolometer for frequency-domain multiplexing | Type | Conference Article | ||
| Year | 2017 | Publication | Proc. 28th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 28th Int. Symp. Space Terahertz Technol. |
| Volume | Issue | Pages  |
120-122 | ||
| Keywords | NbN HEB mixer | ||||
| Abstract | We present the results of characterization of fast and sensitive superconducting antenna-coupled THz direct detector based on NbN hot-electron bolometer (HEB) with AC-bias. We discuss the possibility of implementation of the AC-bias for design the readout system from the multi-element arrays of HEBs using standard technique of frequency-domain multiplexing. We demonstrate experimentally that this approach does not lead to significant deterioration of the HEB sensitivity compared with the value obtained for the same detector with DC- bias. Results of a numerical calculations of the HEB responsivity at AC-bias are in a good agreement with the experiment. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1174 | |||
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| Author | Titova, N; Kardakova, A.; Tovpeko, N; Ryabchun, S.; Mandal, S.; Morozov, D.; Klemencic, G. M.; Giblin, S.R.; Williams, O. A.; Goltsman, G. N. | ||||
| Title | Superconducting diamond films as perspective material for direct THz detectors | Type | Abstract | ||
| Year | 2017 | Publication | Proc. 28th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 28th Int. Symp. Space Terahertz Technol. |
| Volume | Issue | Pages |
82 | ||
| Keywords | KID, HEB, superconducting diamond films, boron-doped diamond films, Al, TiN, Si substrates, NEP | ||||
| Abstract | Superconducting films with a high resistivity in the normal state have established themselves as the best materials for direct THz radiation sensors, such as kinetic inductance detectors (KIDs) [1] and hot electron bolometers (nano-HEBs) [2]. The primary characteristics of the future instrument such as the sensitivity and the response time are determined by the material parameters such as the electron-phonon (e-ph) interaction time, the electron density and the resistivity of the material. For direct detectors, such as KIDs and nano-HEBs, to provide a high sensitivity and low noise one prefer materials with long e-ph relaxation times and low values of the electron density. As a potential material for THz radiation detection we have studied superconducting diamond films. A significant interest to diamond for the development of electronic devices is due to the evolution of its properties with the boron dopant concentration. At a high boron doping concentration, n B ~5·10 20 cm -3 , diamond has been reported to become a superconducting with T c depending on the doping level. Our previous study of energy relaxation in single-crystalline boron-doped diamond films epitaxially grown on a diamond shows a remarkably slow energy-relaxation at low temperatures. The electron-phonon cooling time varies from 400 ns to 700 ns over the temperature range 2.2 K to 1.7 K [3]. In superconducting materials such as Al and TiN, traditionally used in KIDs, the e-ph cooling times at 1.7 K correspond to ~20 ns [4] and ~100 ns [5], correspondingly. Such a noticeable slow e-ph relaxation in boron-doped diamond, in combination with a low value of carrier density (~10 21 cm -3 ) in comparison with typical metals (~10 23 cm -3 ) and a high normal state resistivity (~1500 μΩ·cm) confirms a potential of superconducting diamond for superconducting bolometers and resonator detectors. However, the price and the small substrate growth are of single crystal diamond limit practical applications of homoepitaxial diamond films. As an alternative way with more convenient technology, one can employ heteroepitaxial diamond films grown on large-size Si substrates. Here we report about measurements of e-ph cooling times in superconducting diamond grown on silicon substrate and discuss our expectations about the applicability of boron-doped diamond films to superconducting detectors. Our estimation of limit value of noise-equivalent power (NEP) and the energy resolution of bolometer made from superconducting diamond is order 10 -17 W/Hz 1/2 at 2 K and the energy resolution is of 0.1 eV that corresponds to counting single-photon up to 15 um. The estimation was obtained by using the film thickness of 70 nm and ρ ~ 1500 μΩ·cm, and the planar dimensions that are chosen to couple bolometer with 75 Ω log-spiral antenna. Although the value of NEP is far yet from what might like to have for certain astronomical applications, we believe that it can be improved by a suitable fabrication process. Also the direct detectors, based on superconducting diamond, will offer low noise performance at about 2 K, a temperature provided by inexpensive close-cycle refrigerators, which provides another practical advantage of development and application of these devices. [1] P.K. Day, et. al, Nature, 425, 817, 2003. [2] J. Wei, et al, Nature Nanotech., 3, 496, 2008. [3] A. Kardakova, et al, Phys. Rev. B, 93, 064506, 2016. [4] P. Santhanam and D. Prober, Phys. Rev. B, 29, 3733, 1984 [5] A. Kardakova, et al, Appl. Phys. Lett, vol. 103, p. 252602, 2013. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1173 | |||
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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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| ISSN | 2156-3446 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1330 | |||
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| Author | Pyatkov, F.; Khasminskaya, S.; Kovalyuk, V.; Hennrich, F.; Kappes, M. M.; Goltsman, G. N.; Pernice, W. H. P.; Krupke, R. | ||||
| Title | Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers | Type | Journal Article | ||
| Year | 2017 | Publication | Beilstein J. Nanotechnol. | Abbreviated Journal | Beilstein J. Nanotechnol. |
| Volume | 8 | Issue | Pages |
38-44 | |
| Keywords | carbon nanotubes; CNT; infrared; integrated optics devices; nanomaterials | ||||
| Abstract | Carbon nanotubes (CNTs) have recently been integrated into optical waveguides and operated as electrically-driven light emitters under constant electrical bias. Such devices are of interest for the conversion of fast electrical signals into optical ones within a nanophotonic circuit. Here, we demonstrate that waveguide-integrated single-walled CNTs are promising high-speed transducers for light-pulse generation in the gigahertz range. Using a scalable fabrication approach we realize hybrid CNT-based nanophotonic devices, which generate optical pulse trains in the range from 200 kHz to 2 GHz with decay times below 80 ps. Our results illustrate the potential of CNTs for hybrid optoelectronic systems and nanoscale on-chip light sources. | ||||
| Address | Department of Materials and Earth Sciences, Technische Universitat Darmstadt, Darmstadt 64287, Germany | ||||
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| ISSN | 2190-4286 | ISBN | Medium | ||
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| Notes | PMID:28144563; PMCID:PMC5238692 | Approved | no | ||
| Call Number | RPLAB @ kovalyuk @ | Serial | 1109 | ||
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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 Multi-pixel Hot Electron Bolometer Receiver | Type | Conference Article | ||
| Year | 2017 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
| Volume | 27 | Issue | 4 | Pages |
6 |
| Keywords | Multi-pixel, HEB, silicon-on-insulator, horn array | ||||
| Abstract | We report on the development of a multi-pixel 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 μm 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, |
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| Notes | Approved | no | |||
| Call Number | RPLAB @ kovalyuk @ | Serial | 1111 | ||
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