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| Author | Cherednichenko, S.; Yagoubov, P.; Il'In, K.; Gol'tsman, G.; Gershenzon, E. | ||||
| Title | Large bandwidth of NbN phonon-cooled hot-electron bolometer mixers on sapphire substrates | Type | Conference Article | ||
| Year | 1997 | Publication | Proc. 8th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 8th Int. Symp. Space Terahertz Technol. |
| Volume | Issue | Pages | 245-257 | ||
| Keywords | NbN HEB mixers, fabrication process | ||||
Abstract  |
The bandwidth of NbN phonon-cooled hot electron bolometer mixers has been systematically investigated with respect to the film thickness and film quality variation. The films, 2.5 to 10 mm thick, were fabricated on sapphire substrates using DC reactive magnetron sputtering. All devices consisted of several parallel strips, each 1 1.1 wide and 211 long, placed between Ti-Au contact pads. To measure the gain bandwidth we used two identical BWOs operating in the 120-140 GHz frequency range, one functioning as a local oscillator and the other as a signal source. The majority of the measurements were made at an ambient temperature of 4.5 K with optimal LO and DC bias. The maximum 3 dB bandwidth (about 4 GHz) was achieved for the devices made of films which were 2.5-3.5 nm thick, had a high critical temperature, and high critical current density. A theoretical analysis of bandwidth for these mixers based on the two-temperature model gives a good description of the experimental results if one assumes that the electron temperature is equal to the critical temperature. | ||||
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| Language | Summary Language | Original Title | |||
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| ISSN | ISBN | Medium | |||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Serial | 276 | |||
| Permanent link to this record | |||||
| Author | Cherednichenko, S.; Yagoubov, P.; Il'in, K.; Gol'tsman, G.; Gershenzon, E. | ||||
| Title | Large bandwidth of NbN phonon-cooled hot-electron bolometer mixers | Type | Conference Article | ||
| Year | 1997 | Publication | Proc. 27th Eur. Microwave Conf. | Abbreviated Journal | |
| Volume | 2 | Issue | Pages | 972-977 | |
| Keywords | HEB mixer, fabrication process | ||||
| Abstract |
The bandwidth of NbN phonon-cooled hot electron bolometer mixers has been systematically investigated with respect to the film thickness and film quality variation. The films, 2.5 to 10 nm thick, were fabricated on sapphire substrates using DC reactive magnetron sputtering. All devices consisted of several parallel strips, each 1 um wide and 2 um long, placed between Ti-Au contact pads. To measure the gain bandwidth we used two identical BWOs operating in the 120-140 GHz frequency range, one functioning as a local oscillator and the other as a signal source. The majority of the measurements were made at an ambient temperature of 4.2 K with optimal LO and DC bias. The maximum 3 dB bandwidth (about 4 GHz) was achieved for the devices made of films which were 2.5-3.5 nm thick, had a high critical temperature, and high critical current density. A theoretical analysis of bandwidth for these mixers based on the two-temperature model gives a good description of the experimental results if one assumes that the electron temperature is equal to the critical temperature. | ||||
| Address | Jerusalem, Israel | ||||
| Corporate Author | Thesis | ||||
| Publisher | IEEE | 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 | 27th Eur. Microwave Conf. | ||
| Notes | Approved | no | |||
| Call Number | Serial | 1075 | |||
| Permanent link to this record | |||||
| Author | Sergeev, A.; Karasik, B. S.; Ptitsina, N. G.; Chulkova, G. M.; Il'in, K. S.; Gershenzon, E. M. | ||||
| Title | Electron–phonon interaction in disordered conductors | Type | Journal Article | ||
| Year | 1999 | Publication | Phys. Rev. B Condens. Matter | Abbreviated Journal | Phys. Rev. B Condens. Matter |
| Volume | 263-264 | Issue | Pages | 190-192 | |
| Keywords | disordered conductors, electron-phonon interaction | ||||
| Abstract |
The electron–phonon interaction is strongly modified in conductors with a small value of the electron mean free path (impure metals, thin films). As a result, the temperature dependencies of both the inelastic electron scattering rate and resistivity differ significantly from those for pure bulk materials. Recent complex measurements have shown that modified dependencies are well described at K by the electron interaction with transverse phonons. At helium temperatures, available data are conflicting, and cannot be described by an universal model. | ||||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0921-4526 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | Serial | 1765 | |||
| Permanent link to this record | |||||
| Author | Henrich, D.; Dorner,S.; Hofherr, M.; Il'in, K.; Semenov, A.; Heintze, E.; Scheffler, M.; Dressel, M.; Siegel, M. | ||||
| Title | Broadening of hot-spot response spectrum of superconducting NbN nanowire single-photon detector with reduced nitrogen content | Type | Journal Article | ||
| Year | 2012 | Publication | Abbreviated Journal | J. Appl. Phys. | |
| Volume | 112 | Issue | Pages | ||
| Keywords | SSPD, SNSPD, magnetron sputtering, spectrum, NbN film, nitrogen concentration | ||||
| Abstract |
The spectral detection efficiency and the dark count rate of superconducting nanowire single-photon detectors (SNSPD) have been studied systematically on detectors made from thin NbN films with different chemical compositions. Reduction of the nitrogen content in the 4 nm thick NbN films results in a decrease of the dark count rates more than two orders of magnitude and in a red shift of the cut-off wavelength of the hot-spot SNSPD response. The observed phenomena are explained by an improvement of uniformity of NbN films that has been confirmed by a decrease of resistivity and an increase of the ratio of the measured critical current to the depairing current. The latter factor is considered as the most crucial for both the cut-off wavelength and the dark count rates of SNSPD. Based on our results we propose a set of criteria for material properties to optimize SNSPD in the infrared spectral region. VC 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4757625] |
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| Corporate Author | D. Henrich, S. Dorner, M. Hofherr, K. Il'in, A. Semenov, E. Heintze, M. Scheffler, M. Dressel, M. Siegel | Thesis | |||
| Publisher | Place of Publication | Editor | |||
| Language | English | Summary Language | Original Title | Broadening of hot-spot response spectrum of superconducting NbN nanowire single-photon detector with reduced nitrogen content | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | RPLAB @ seleznev @ | Serial | 877 | ||
| Permanent link to this record | |||||
| Author | Karasik, B. S.; Il'in, K. S.; Ptitsina, N. G.; Gol'tsman, G. N.; Gershenzon, E. M.; Pechen', E. V.; Krasnosvobodtsev, S. I. | ||||
| Title | Electron-phonon scattering rate in impure NbC films | Type | Abstract | ||
| Year | 1998 | Publication | NASA/ADS | Abbreviated Journal | NASA/ADS |
| Volume | Issue | Pages | Y35.08 | ||
| Keywords | NbC films | ||||
| Abstract |
The study of the electron-phonon interaction in thin (20 nm) NbC films with electron mean free path l=2-13 nm gives an evidence that electron scattering is significantly modified due to the interference between electron-phonon and elastic electron scattering from impurities. The interference ~T^2-term, which is proportional to the residual resistivity, dominates over the Bloch-Grüneisen contribution to resistivity at low temperatures up to 60 K. The electron energy relaxation rate is directly measured via the relaxation of hot electrons heated by modulated electromagnetic radiation. In the temperature range 1.5 – 10 K the relaxation rate shows a weak dependence on the electron mean free path and strong temperature dependence T^n with the exponent n = 2.5-3. This behaviour is well explained by the theory of the electron-phonon-impurity interference taking into account the electron coupling with transverse phonons determined from the resistivity data. | ||||
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| Area | Expedition | Conference | American Physical Society, Annual March Meeting, March 16-20, 1998 Los Angeles, CA | ||
| Notes | Approved | no | |||
| Call Number | Serial | 1591 | |||
| Permanent link to this record | |||||