toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Trifonov, Andrey; Tong, C. Edward; Lobanov, Yury; Kaurova, Natalia; Blundell, Raymond; Gol’tsman, Gregory url  openurl
  Title An investigation of the DC and IF performance of silicon-membrane HEB mixer elements Type Conference Article
  Year 2015 Publication Proc. 26th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 26th Int. Symp. Space Terahertz Technol.  
  Volume (up) Issue Pages 40  
  Keywords silicon-membrane HEB waveguide mixer  
  Abstract We report on our initial development towards a 2x2 multi-pixel HEB waveguide mixer for operation at 1.4 THz. We have successfully fabricated devices comprising an NbN bridge integrated with antenna test structure using a silicon membrane as the supporting substrate. DC measurements of the test chips demonstrate critical current from 0.1 – 1mA depending on the size of device, with T c of around 10 K and ΔTc ~ 0.8 K.  
  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 1160  
Permanent link to this record
 

 
Author Samsonova, Alena; Zolotov, Philipp; Baeva, Elmira; Lomakin, Andrey; Titova, Nadezhda; Kardakova, Anna; Goltsman, Gregory doi  openurl
  Title Signatures of surface magnetic disorder in thin niobium films Type Journal Article
  Year 2021 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal  
  Volume (up) Issue Pages 1-1  
  Keywords Temperature measurement, Temperature dependence, Superconducting magnets, Superconducting transition temperature, Substrates, Resistance, Scattering  
  Abstract We present our studies on the evolution of the normal and superconducting properties with thickness of thin Nb films with a low level of non-magnetic disorder (kFl 150 for the thickest film in the set). The analysis of the superconducting behavior points to the presence of magnetic moments, hidden in the native oxide on the surface of Nb films. Using the Abrikosov-Gorkov theory, we obtain the density of surface magnetic moments of 1013 cm-2, which is in agreement with the previously reported data for Nb films.  
  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 1162  
Permanent link to this record
 

 
Author Baeva, E. M.; Titova, N. A.; Veyrat, L.; Sacépé, B.; Semenov, A. V.; Goltsman, G. N.; Kardakova, A. I.; Khrapai, V. S. url  openurl
  Title Thermal relaxation in metal films bottlenecked by diffuson lattice excitations of amorphous substrates Type Miscellaneous
  Year 2021 Publication arXiv Abbreviated Journal arXiv  
  Volume (up) Issue Pages  
  Keywords metal films, NbN, InOx, Au/Ni, thermal relaxation  
  Abstract Here we examine the role of the amorphous insulating substrate in the thermal relaxation in thin NbN, InOx, and Au/Ni films at temperatures above 5 K. The studied samples are made up of metal bridges on an amorphous insulating layer lying on or suspended above a crystalline substrate. Noise thermometry was used to measure the electron temperature Te of the films as a function of Joule power per unit of area P2D. In all samples, we observe the dependence P2D∝Tne with the exponent n≃2, which is inconsistent with both electron-phonon coupling and Kapitza thermal resistance. In suspended samples, the functional dependence of P2D(Te) on the length of the amorphous insulating layer is consistent with the linear T-dependence of the thermal conductivity, which is related to lattice excitations (diffusons) for the phonon mean free path smaller than the dominant phonon wavelength. Our findings are important for understanding the operation of devices embedded in amorphous dielectrics.  
  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 1163  
Permanent link to this record
 

 
Author Seliverstov, Sergey V.; Rusova, Anastasia A.; Kaurova, Natalya S.; Voronov, Boris M.; Goltsman, Gregory N. openurl 
  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 (up) 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.  
  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 1174  
Permanent link to this record
 

 
Author Antipov, S.; Trifonov, A.; Krause, S.; Meledin, D.; Desmaris, V.; Belitsky, V.; Gol’tsman, G. openurl 
  Title Gain bandwidth of NbN HEB mixers on GaN buffer layer operating at 2 THz local oscillator frequency Type Conference Article
  Year 2017 Publication Proc. 28th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 28th Int. Symp. Space Terahertz Technol.  
  Volume (up) Issue Pages 147-148  
  Keywords NbN HEB mixers, GaN buffer-layer, IF bandwidth  
  Abstract In this paper, we present IF bandwidth measurement results of NbN HEB mixers, which are employing NbN thin films grown on a GaN buffer-layer. The HEB mixers were operated in the heterodyne regime at a bath temperature of approximately 4.5 K and with a local oscillator operating at a frequency of 2 THz. A quantum cascade laser served as the local oscillator and a reference synthesizer based on a BWO generator (130-160 GHz) and a semiconductor superlattice (SSL) frequency multiplier was used as a signal source. By changing the LO frequency it was possible to record the IF response or gain bandwidth of the HEB with a spectrum analyzer at the operation point, which yielded lowest noise temperature. The gain bandwidth that was recorded in the heterodyne regime at 2 THz amounts to approximately 5 GHz and coincides well with a measurement that has been performed at elevated bath temperatures and lower LO frequency of 140 GHz. These findings strongly support that by using a GaN buffer-layer the phonon escape time of NbN HEBs can be significantly lower as compared to e.g. Si substrate, thus, providing higher gain bandwidth.  
  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 1175  
Permanent link to this record
 

 
Author Bakhvalova, T.; Belkin, M. E.; Kovalyuk, V. V.; Prokhodtcov, A. I.; Goltsman, G. N.; Sigov, A. S. url  doi
openurl 
  Title Studying key principles for design and fabrication of silicon photonic-based beamforming networks Type Conference Article
  Year 2019 Publication PIERS-Spring Abbreviated Journal PIERS-Spring  
  Volume (up) Issue Pages 745-751  
  Keywords silicon photonics, TriPleX platform  
  Abstract In the paper, we address key principles for computer-aided design and fabrication of silicon-photonics-based optical beamforming network selecting the optimal approach by simulation and experimental results. To clarify the consideration, the study is conducted on the example of a widely used binary switchable silicon-nitride optical beamforming network based on TriPleX platform. Comparison of simulation results and experimental studies of the prototype shows that the relative error due to technological imperfections does not exceed 3%. According to the estimation, such an error introduces insignificant distortion in the radiation pattern of the referred antenna array.  
  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 9017646 Serial 1186  
Permanent link to this record
 

 
Author Krause, S.; Mityashkin, V.; Antipov, S.; Gol'tsman, G.; Meledin, D.; Desmaris, V.; Belitsky, V.; Rudzinski, M. url  openurl
  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 (up) Issue Pages 30-32  
  Keywords 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 Shcherbatenko, M.; Lobanov, Y.; Kovalyuk, V.; Korneev, A.; Gol'tsman, G. N. url  openurl
  Title Photon counting detector as a mixer with picowatt local oscillator power requirement Type Conference Article
  Year 2016 Publication Proc. 27th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 27th Int. Symp. Space Terahertz Technol.  
  Volume (up) Issue Pages 110  
  Keywords SSPD mixer, SNSPD  
  Abstract At the current stage of the heterodyne receiver technology, great attention is paid to the development of detector arrays and matrices comprising many detectors on a single wafer. However, any traditional THz detector (such as SIS, HEB, or Schottky diode) requires quite a noticeable amount of Local Oscillator (LO) power which scales with the matrix size, and the total amount of the LO power needed is much greater than that available from compact and handy solid state sources. Substantial reduction of the LO power requirement may be obtained with a photon-counting detector used as a mixer. This approach, mentioned earlier in [1,2] provides a number of advantages. Thus, sensitivity of such a detector would be at the quantum limit (because of the photon-counting nature of the detector) and just a few LO photons for the mixing would be required leading to a possible breakthrough in the matrix receiver development. In addition, the receiver could be easily tuned from the heterodyne to the direct detection mode without any loss in its sensitivity with the latter limited only by the quantum efficiency of the detector used. We demonstrate such a technique with the use of the Superconducting Nanowire Single Photon Detector(SNSPD)[3] irradiated by both 1.5 μm LO with a tiny amount of power (from a few picowatts down to femtowatts) facing the detector, and the test signal with a power significantly less than that of the LO. The SNSPD was operated in the current mode and the bias current was slightly below its critical value. Irradiating the detector with either the LO or the signal source produced voltage pulses which are statistically evenly distributed and could be easily counted by a lab counter or oscilloscope. Irradiating the detector by the both lasers simultaneously produced pulses at the frequency f m which is the exact difference between the frequencies at which the two lasers operate. f m could be deduced form either counts statistics integrated over a sufficient time interval or with the help of an RF spectrum analyzer. In addition to the chip SNSPD with normal incidence coupling, we use the detectors with a travelling wave geometry design [4]. In this case a niobium nitride nanowire is placed on the top of a nanophotonic waveguide, thus increasing the efficient interaction length. Integrated device scheme allows us to measure the optical losses with high accuracy. Our approach is fully scalable and, along with a large number of devices integrated on a single chip can be adapted to the mid and far IR ranges. This work was supported in part by the Ministry of Education and Science of the Russian Federation, contract no. 14.B25.31.0007 and by RFBR grant # 16-32-00465. 1. Leaf A. Jiang and Jane X. Luu, ―Heterodyne detection with a weak local oscillator, Applied Optics Vol. 47, Issue 10, pp. 1486-1503 (2008) 2. Matsuo H. ―Requirements on Photon Counting Detectors for Terahertz Interferometry J Low Temp Phys (2012) 167:840–845 3. A. Semenov, G. Gol'tsman, A. Korneev, “Quantum detection by current carrying superconducting film”, Physica C, 352, pp. 349-356 (2001) 4. O. Kahl, S. Ferrari, V. Kovalyuk, G. N. Goltsman, A. Korneev, and W. H. P. Pernice, ―Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths., Sci. Rep., vol. 5, p. 10941, (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 1203  
Permanent link to this record
 

 
Author Trifonov, A.; Tong, C.-Y. E.; Lobanov, Y.; Kaurova, N.; Blundell, R.; Goltsman, G. url  openurl
  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 (up) Issue Pages 121  
  Keywords 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 Kuzin, Aleksei; Elmanov, Ilia; Kovalyuk, Vadim; An, Pavel; Goltsman, Gregory doi  isbn
openurl 
  Title Silicon nitride focusing grating coupler for input and output light of NV-centers Type Conference Article
  Year 2020 Publication Proc. 32-nd EMSS Abbreviated Journal Proc. 32-nd EMSS  
  Volume (up) Issue Pages 349-353  
  Keywords NV-centers, focusing grating coupler  
  Abstract Here we presented the numerical results for the calculation of focusing grating coupler efficiency in the visible wavelength range. Using the finite element method, the optimal geometric parameters, including filling factor and grating period for a central wavelength of 637 nm, were found. Obtained results allow to input/output single-photon radiation from NV-centers, and can be used for research and development of a scalable on-chip quantum optical computing.  
  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 2724-0029 ISBN 978-88-85741-44-7 Medium  
  Area Expedition Conference 32nd European Modeling & Simulation Symposium  
  Notes Approved no  
  Call Number Serial 1841  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: