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| Author | Lusche, Robert; Semenov, Alexey; Huebers, Heinz-Willhelm; Ilin, Konstantin; Siegel, Michael; Korneeva, Yuliya; Trifonov, Andrey; Korneev, Alexander; Goltsman, Gregory | ||||
| Title | Effect of the wire geometry and an externally applied magnetic field on the detection efficiency of superconducting nanowire single-photon detectors | Type | Abstract | ||
| Year | 2013 | Publication | INIS | Abbreviated Journal  |
INIS |
| Volume | 46 | Issue | 8 | Pages | 1-3 |
| Keywords | TaN, NbN SSPD, SNSPD | ||||
| Abstract | The interest in single-photon detectors in the near-infrared wavelength regime for applications, e.g. in quantum cryptography has immensely increased in the last years. Superconducting nanowire single-photon detectors (SNSPD) already show quite reasonable detection efficiencies in the NIR which can even be further improved. Novel theoretical approaches including vortex-assisted photon counting state that the detection efficiency in the long wavelength region can be enhanced by the detector geometry and an applied magnetic field. We present spectral measurements in the wavelength range from 350-2500 nm of the detection efficiency of meander-type TaN and NbN SNSPD with varying nanowire line width from 80 to 250 nm. Due to the used experimental setup we can accurately normalize the measured spectra and are able to extract the intrinsic detection efficiency (IDE) of our detectors. The results clearly indicate an improvement of the IDE depending on the wire width according to the theoretic models. Furthermore we experimentally found that the smallest detectable photon-flux can be increased by applying a small magnetic field to the detectors. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1374 | |||
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| Author | Beck, Matthias; Leiderer, Paul; Kabanov, Viktor V.; Gol'tsman, Gregory; Helm, Manfred; Demsar, Jure | ||||
| Title | Energy-gap dynamics of a superconductor NbN studied by time-resolved terahertz spectroscopy | Type | Abstract | ||
| Year | 2012 | Publication | INIS | Abbreviated Journal |
INIS |
| Volume | 45 | Issue | 12 | Pages | 1-3 |
| Keywords | NbN energy gap | ||||
| Abstract | Using time-resolved terahertz (THz) spectroscopy we performed direct studies of the photoinduced suppression and recovery of the SC gap in a conventional SC NbN. Both processes are found to be strongly temperature and excitation density dependent. The analysis of the data with the established phenomenological Rothwarf-Taylor model enabled us to determine the important microscopic constants: the Cooper pair-breaking rate via phonon absorption and the bare quasiparticle recombination rate. From the latter we were able to extract the dimensionless electron-phonon coupling constant, λ=1.1±0.1, in excellent agreement with theoretical estimates. The technique also allowed us to determine the absorbed energy required to suppress SC, which in NbN equals the thermodynamic condensation energy (in cuprates the two differ by an order of magnitude). Finally, we present the first studies of dynamics following resonant excitation with intense narrow band THz pulses tuned to above and below the superconducting gap. These suggest an additional process, particularly pronounced near Tc, that could be attributed to amplification of SC via effective quasiparticle cooling. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1383 | |||
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| Author | Slysz, W.; Wegrzecki, M.; Papis, E.; Gol'tsman, G. N.; Verevkin, A.; Sobolewski, R. | ||||
| Title | A method of optimization of the NbN superconducting single-photon detector | Type | Miscellaneous | ||
| Year | 2004 | Publication | INIS | Abbreviated Journal |
INIS |
| Volume | 36 | Issue | 27 | Pages | 1-2 |
| Keywords | NbN SSPD, SNSPD | ||||
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| Area | Expedition | Conference | 5-th International Symposium Ion Implantation and Other Applications of Ions and Electrons, ION | ||
| Notes | Reference num. 36060124 | Approved | no | ||
| Call Number | Serial | 1485 | |||
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| Author | Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Gol'tsman, G. N.; Verevkin, M.; Sobolewski, R. | ||||
| Title | NbN superconducting single-photon detectors coupled with a communication fiber | Type | Miscellaneous | ||
| Year | 2004 | Publication | INIS | Abbreviated Journal |
INIS |
| Volume | 37 | Issue | 2 | Pages | 1-2 |
| Keywords | NbN SSPD, SNSPD | ||||
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| Address | Stare Jablonki, Poland | ||||
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| Area | Expedition | Conference | 8-th Electron Technology Conference ELTE | ||
| Notes | Approved | no | |||
| Call Number | Serial | 1486 | |||
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| Author | Hübers, H.-W.; Schubert, J.; Krabbe, A.; Birk, M.; Wagner, G.; Semenov, A.; Gol’tsman, G.; Voronov, B.; Gershenzon, E. | ||||
| Title | Parylene anti-reflection coating of a quasi-optical hot-electron-bolometric mixer at terahertz frequencies | Type | Journal Article | ||
| Year | 2001 | Publication | Infrared Physics & Technology | Abbreviated Journal |
Infrared Physics & Technology |
| Volume | 42 | Issue | 1 | Pages | 41-47 |
| Keywords | NbN HEB mixers, anti-reflection coating | ||||
| Abstract | Parylene C was investigated as anti-reflection coating for silicon at terahertz frequencies. Measurements with a Fourier-transform spectrometer show that the transmittance of pure silicon can be improved by about 30% when applying a layer of Parylene C with a quarter wavelength optical thickness. The 10% bandwidth of this coating extends from 1.5 to 3 THz for a center frequency of 2.3–2.5 THz, where the transmittance is constant. Heterodyne measurements demonstrate that the noise temperature of a hot-electron-bolometric mixer can be reduced significantly by coating the silicon lens of the hybrid antenna with a quarter wavelength Parylene C layer. Compared to the same mixer with an uncoated lens the improvement is about 30% at a frequency of 2.5 THz. | ||||
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| ISSN | 1350-4495 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1548 | |||
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| Author | Gol'tsman, G. N. | ||||
| Title | Hot electron bolometric mixers: new terahertz technology | Type | Journal Article | ||
| Year | 1999 | Publication | Infrared Physics & Technology | Abbreviated Journal |
Infrared Physics & Technology |
| Volume | 40 | Issue | 3 | Pages | 199-206 |
| Keywords | NbN HEB mixers | ||||
| Abstract | This paper presents an overview of recent results for NbN phonon-cooled hot electron bolometric (HEB) mixers. The noise temperature of the receivers based on both quasioptical and waveguide versions of HEB mixers has crossed the level of 1 K GHz−1 at 430 GHz (410 K), 600–650 GHz (480 K), 750 GHz (600 K), 810 GHz (780 K) and is close to that level at 1.1 THz (1250 K) and 2.5 THz (4500 K). The gain bandwidth measured for quasioptical HEB mixer at 620 GHz reached 4 GHz and the noise temperature bandwidth was almost 8 GHz. Local oscillator power requirements are about 1 μW for mixers made by photolithography and about 100 nW for mixers made by e-beam lithography. A waveguide version of 800 GHz receiver was installed at the Submillimeter Telescope Observatory on Mt. Graham, AZ, to conduct astronomical observations of known submillimeter lines (CO, J=7→6, CI, J=2→1). It was proved that the receiver works as a practical instrument. | ||||
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| ISSN | 1350-4495 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1570 | |||
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| Author | Sobolewski, Roman; Xu, Ying; Zheng, Xuemei; Williams, Carlo; Zhang, Jin; Verevkin, Aleksandr; Chulkova, Galina; Korneev, Alexander; Lipatov, Andrey; Okunev, Oleg; Smirnov, Konstantin; Gol'tsman, Gregory N. | ||||
| Title | Spectral sensitivity of the NbN single-photon superconducting detector | Type | Journal Article | ||
| Year | 2002 | Publication | IEICE Trans. Electron. | Abbreviated Journal |
IEICE Trans. Electron. |
| Volume | E85-C | Issue | 3 | Pages | 797-802 |
| Keywords | NbN SSPD, SNSPD | ||||
| Abstract | We report our studies on the spectral sensitivity of superconducting NbN thin-film single-photon detectors (SPD's) capable of GHz counting rates of visible and near-infrared photons. In particular, it has been shown that a NbN SPD is sensitive to 1.55-µm wavelength radiation and can be used for quantum communication. Our SPD's exhibit experimentally measured intrinsic quantum efficiencies from 20% at 800 nm up to 1% at 1.55-µm wavelength. The devices demonstrate picosecond response time (<100 ps, limited by our readout system) and negligibly low dark counts. Spectral dependencies of photon counting of continuous-wave, 0.4-µm to 3.5-µm radiation, and 0.63-µm, 1.33-µm, and 1.55-µm laser-pulsed radiations are presented for the single-stripe-type and meander-type devices. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1531 | |||
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| Author | Korneeva, Yuliya; Florya, Irina; Vdovichev, Sergey; Moshkova, Mariya; Simonov, Nikita; Kaurova, Natalia; Korneev, Alexander; Goltsman, Gregory | ||||
| Title | Comparison of hot-spot formation in NbN and MoN thin superconducting films after photon absorption | Type | Conference Article | ||
| Year | 2017 | Publication | IEEE Transactions on Applied Superconductivity | Abbreviated Journal |
IEEE Transactions on Applied Superconductiv |
| Volume | 27 | Issue | 4 | Pages | 5 |
| Keywords | Thin film devices, Superconducitng photoncounting devices, Nanowire single-photon detectors | ||||
| 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 MoNx detectors we study the dependence of detection efficiency on bias current, photon energy, and strip width and compare it with NbN SSPD. We observe non-linear current-energy dependence in MoNx SSPD and more pronounced plateaus in dependences of detection efficiency on bias current which we attribute to longer electronphonon interaction time. |
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| Notes | Approved | no | |||
| Call Number | RPLAB @ kovalyuk @ | Serial | 1114 | ||
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| Author | Shurakov, A.; Tong, Cheuk-yu E.; Grimes, P.; Blundell, R.; Golt'sman, G. | ||||
| Title | A microwave reflection readout scheme for hot electron bolometric direct detector | Type | Journal Article | ||
| Year | 2015 | Publication | IEEE Trans. THz Sci. Technol. | Abbreviated Journal |
IEEE Trans. THz Sci. Technol. |
| Volume | 5 | Issue | Pages | 81-84 | |
| Keywords | HEB detectors | ||||
| Abstract | In this paper, we propose and present data from a fast THz detector based on the repurpose of hot electron bolometer mixers (HEB) fabricated from superconducting NbN thinfilm. This detector is essentially a traditional NbN bolometer element that operates under the influence of a microwave pump. The in-jected microwave power serves the dual purpose of enhancing the detector sensitivity and reading out the impedance changes of the device in response to incidentTHz radiation. We have measured an optical Noise Equivalent Power of 4 pW/ Hz for our detector at a bath temperature of 4.2 K. The measurement frequency was 0.83 THz and the modulation frequency was 1.48 kHz. The readout scheme is versatile and facilitates both high-speed operation as well as multi-pixel applications. |
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| Notes | Approved | no | |||
| Call Number | RPLAB @ atomics90 @ | Serial | 950 | ||
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| Author | Klapwijk, T. M.; Semenov, A. V. | ||||
| Title | Engineering physics of superconducting hot-electron bolometer mixers | Type | Journal Article | ||
| Year | 2017 | Publication | IEEE Trans. THz Sci. Technol. | Abbreviated Journal |
IEEE Trans. THz Sci. Technol. |
| Volume | 7 | Issue | 6 | Pages | 627-648 |
| Keywords | HEB mixers | ||||
| Abstract | Superconducting hot-electron bolometers are presently the best performing mixing devices for the frequency range beyond 1.2 THz, where good-quality superconductor-insulator-superconductor devices do not exist. Their physical appearance is very simple: an antenna consisting of a normal metal, sometimes a normal-metal-superconductor bilayer, connected to a thin film of a narrow short superconductor with a high resistivity in the normal state. The device is brought into an optimal operating regime by applying a dc current and a certain amount of local-oscillator power. Despite this technological simplicity, its operation has found to be controlled by many different aspects of superconductivity, all occurring simultaneously. A core ingredient is the understanding that there are two sources of resistance in a superconductor: a charge-conversion resistance occurring at a normal-metal-superconductor interface and a resistance due to time-dependent changes of the superconducting phase. The latter is responsible for the actual mixing process in a nonuniform superconducting environment set up by the bias conditions and the geometry. The present understanding indicates that further improvement needs to be found in the use of other materials with a faster energy relaxation rate. Meanwhile, several empirical parameters have become physically meaningful indicators of the devices, which will facilitate the technological developments. | ||||
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| ISSN | 2156-342X | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 1292 | |||
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