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Author Beck, M.; Klammer, M.; Lang, S.; Leiderer, P.; Kabanov, V. V.; Gol'tsman, G. N.; Demsar, J.
Title Energy-gap dynamics of superconducting NbN thin films studied by time-resolved terahertz spectroscopy Type Journal Article
Year 2011 Publication Phys. Rev. Lett. Abbreviated Journal Phys. Rev. Lett.
Volume 107 Issue 17 Pages 4
Keywords NbN thin film, energy gap dynamics
Abstract (down) Using time-domain terahertz spectroscopy we performed direct studies of the photoinduced suppression and recovery of the superconducting gap in a conventional BCS superconductor 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 bare quasiparticle recombination rate, the Cooper pair-breaking rate and the electron-phonon coupling constant, λ=1.1±0.1, which is in excellent agreement with theoretical estimates.
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Notes Approved no
Call Number RPLAB @ gujma @ Serial 641
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Author Kawamura, J.; Hunter, T. R.; Tong, C. Y. E.; Blundell, R.; Papa, D. C.; Patt, F.; Peters, W.; Wilson, T.; Henkel, C.; Goltsman, G.; Gershenzon, E.
Title Ground-based terahertz CO spectroscopy towards Orion Type Journal Article
Year 2002 Publication A&A Abbreviated Journal A&A
Volume 394 Issue 1 Pages 271-274
Keywords HEB mixers, applications
Abstract (down) Using a superconductive hot-electron bolometer heterodyne receiver on the 10-m Heinrich Hertz Telescope on Mount Graham, Arizona, we have obtained velocity-resolved 1.037 THz CO () spectra toward several positions along the Orion Molecular Cloud (OMC-1) ridge. We confirm the general results of prior observations of high-J CO lines that show that the high temperature, , high density molecular gas, , is quite extended, found along a ~ region centered on BN/KL. However, our observations have significantly improved angular resolution, and with a beam size of we are able to spatially and kinematically discriminate the emission originating in the extended quiescent ridge from the very strong and broadened emission originating in the compact molecular outflow. The ridge emission very close to the BN/KL region appears to originate from two distinct clouds along the line of sight with and ≈ . The former component dominates the emission to the south of BN/KL and the latter to the north, with a turnover point coincident with or near BN/KL. Our evidence precludes a simple rotation of the inner ridge and lends support to a model in which there are multiple molecular clouds along the line of sight towards the Orion ridge.
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Notes Approved no
Call Number Serial 322
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Author Trifonov, A.; Tong, C.-Y. E.; Blundell, R.; Ryabchun, S.; Gol'tsman, G.
Title Probing the stability of HEB mixers with microwave injection Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 25 Issue 3 Pages 2300404 (1 to 4)
Keywords NbN HEB mixer, stability, Allan-variance
Abstract (down) Using a microwave probe as a tool, we have performed experiments aimed at understanding the origin of the output-power fluctuations in hot-electron-bolometer (HEB) mixers. We use a probe frequency of 1.5 GHz. The microwave probe picks up impedance changes of the HEB, which are examined upon demodulation of the reflected wave outside the cryostat. This study shows that the HEB mixer operates in two different regimes under a terahertz pump. At a low pumping level, strong pulse modulation is observed, as the device switches between the superconducting state and the normal state at a rate of a few megahertz. When pumped much harder, to approximate the low-noise mixer operating point, residual modulation can still be observed, showing that the HEB mixer is intrinsically unstable even in the resistive state. Based on these observations, we introduced a low-frequency termination to the HEB mixer. By terminating the device in a 50-Ω resistor in the megahertz frequency range, we have been able to improve the output-power Allan time of our HEB receiver by a factor of four to about 10 s for a detection bandwidth of 15 MHz, with a corresponding gain fluctuation of about 0.035%.
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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 1355
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Author Pernice, W. H. P.; Schuck, C.; Minaeva, O.; Li, M.; Goltsman, G. N.; Sergienko, A. V.; Tang, H. X.
Title High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits Type Journal Article
Year 2012 Publication Nat. Commun. Abbreviated Journal Nat. Commun.
Volume 3 Issue Pages 1325 (1 to 10)
Keywords waveguide SSPD
Abstract (down) Ultrafast, high-efficiency single-photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. However, imperfect modal matching and finite photon absorption rates have usually limited their maximum attainable detection efficiency. Here we demonstrate superconducting nanowire detectors atop nanophotonic waveguides, which enable a drastic increase of the absorption length for incoming photons. This allows us to achieve high on-chip single-photon detection efficiency up to 91% at telecom wavelengths, repeatable across several fabricated chips. We also observe remarkably low dark count rates without significant compromise of the on-chip detection efficiency. The detectors are fully embedded in scalable silicon photonic circuits and provide ultrashort timing jitter of 18 ps. Exploiting this high temporal resolution, we demonstrate ballistic photon transport in silicon ring resonators. Our direct implementation of a high-performance single-photon detector on chip overcomes a major barrier in integrated quantum photonics.
Address Department of Electrical Engineering, Yale University, New Haven, Connecticut 06511, USA
Corporate Author Thesis
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Medium
Area Expedition Conference
Notes PMID:23271658; PMCID:PMC3535416 Approved no
Call Number Serial 1375
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Author Pernice, W.; Schuck, C.; Li, M.; Goltsman, G. N.; Sergienko, A. V.; Tang, H. X.
Title High speed travelling wave single-photon detectors with near-unity quantum efficiency Type Journal Article
Year 2011 Publication arXiv Abbreviated Journal arXiv
Volume Issue Pages 1-14
Keywords SPD
Abstract (down) Ultrafast, high quantum efficiency single photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. Close-to-unity photon detection efficiency is essential for scalable measurement-based quantum computation, quantum key distribution, and loophole-free Bell experiments. However, imperfect modal matching and finite photon absorption rates have usually limited the maximum attainable detection efficiency of single photon detectors. Here we demonstrate a superconducting nanowire detector atop nanophotonic waveguides and achieve single photon detection efficiency up to 94% at telecom wavelengths. Our detectors are fully embedded in a scalable, low loss silicon photonic circuit and provide ultrashort timing jitter of 18ps at multi-GHz detection rates. Exploiting this high temporal resolution we demonstrate ballistic photon transport in silicon ring resonators. The direct implementation of such a detector with high quantum efficiency, high detection speed and low jitter time on chip overcomes a major barrier in integrated quantum photonics.
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Publisher Place of Publication arXiv:1108.5299 Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number RPLAB @ gujma @ Serial 661
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Author Vetter, A.; Ferrari, S.; Rath, P.; Alaee, R.; Kahl, O.; Kovalyuk, V.; Diewald, S.; Goltsman, G. N.; Korneev, A.; Rockstuhl, C.; Pernice, W. H. P.
Title Cavity-enhanced and ultrafast superconducting single-photon detectors Type Journal Article
Year 2016 Publication Nano Lett. Abbreviated Journal Nano Lett.
Volume 16 Issue 11 Pages 7085-7092
Keywords SSPD; SNSPD; multiphoton detection; nanophotonic circuit; photonic crystal cavity
Abstract (down) Ultrafast single-photon detectors with high efficiency are of utmost importance for many applications in the context of integrated quantum photonic circuits. Detectors based on superconductor nanowires attached to optical waveguides are particularly appealing for this purpose. However, their speed is limited because the required high absorption efficiency necessitates long nanowires deposited on top of the waveguide. This enhances the kinetic inductance and makes the detectors slow. Here, we solve this problem by aligning the nanowire, contrary to usual choice, perpendicular to the waveguide to realize devices with a length below 1 mum. By integrating the nanowire into a photonic crystal cavity, we recover high absorption efficiency, thus enhancing the detection efficiency by more than an order of magnitude. Our cavity enhanced superconducting nanowire detectors are fully embedded in silicon nanophotonic circuits and efficiently detect single photons at telecom wavelengths. The detectors possess subnanosecond decay ( approximately 120 ps) and recovery times ( approximately 510 ps) and thus show potential for GHz count rates at low timing jitter ( approximately 32 ps). The small absorption volume allows efficient threshold multiphoton detection.
Address Institute of Physics, University of Munster , 48149 Munster, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Medium
Area Expedition Conference
Notes PMID:27759401 Approved no
Call Number Serial 1208
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Author Gershenzon, E. M.; Gol’tsman, G. N.; Semenov, A. D.; Sergeev, A. V.
Title Mechanism of picosecond response of granular YBaCuO films to electromagnetic radiation Type Journal Article
Year 1991 Publication IEEE Trans. Magn. Abbreviated Journal IEEE Trans. Magn.
Volume 27 Issue 2 Pages 1321-1324
Keywords YBCO HTS detectors
Abstract (down) Ultrafast mechanisms of radiation detection in granular YBaCuO films are studied in the wide wavelength range from millimeter waves to near infrared. With an increase in radiation frequency, the Josephson detection at the grain-boundary weak links is replaced by electron heating into the grains. This change occurs in the submillimeter wavelength range. The electron-phonon relaxation time tau /sub eph/ is determined from direct measurements, quasi-stationary electron heating measurements, and the frequency dependence of the current at which maximum voltage shift is observed. The temperature dependence of tau /sub eph/ at T<or=40 K was found to be tau /sub eph/ approximately T/sup -1/. The results show that detectors with a response time of a few picoseconds at nitrogen temperature are attainable.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1941-0069 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1679
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Author Karasik, B. S.; Milostnaya, I. I.; Zorin, M. A.; Elantev, A. I.; Gol'tsman, G. N.; Gershenzon, E. M.
Title High speed current switching of homogeneous YBaCuO film between superconducting and resistive states Type Journal Article
Year 1995 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 5 Issue 2 Pages 3042-3045
Keywords YBCO HTS HEB switches
Abstract (down) Transitions of thin structured YBaCuO films from superconducting (S) to normal (N) state and back induced by a supercritical current pulse has been studied. A subnanosecond stage in the film resistance dynamic has been observed. A more gradual (nanosecond) ramp in the time dependence of the resistance follows the fast stage. The fraction of the film resistance which is attained during the fast S-N stage rises with the current amplitude. Subnanosecond N-S switching is more pronounced for smaller amplitudes of driving current and for shorter pulses. The phenomena observed are viewed within the framework of an electron heating model. The expected switching time and repetition rate of an optimized current controlling device are estimated to be 1-2 ps and 80 GHz respectively.
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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 1620
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Author Gershenzon, E. M.; Gol'tsman, G. N.; Potapov, V. D.; Sergeev, A. V.
Title Restriction of microwave enhancement of superconductivity in impure superconductors due to electron-electron interaction Type Journal Article
Year 1990 Publication Solid State Communications Abbreviated Journal Solid State Communications
Volume 75 Issue 8 Pages 639-641
Keywords impure superconductors
Abstract (down) Transition from microwave enhancement of supercurrent to superconductivity suppression is investigated in impure superconductors. It is demonstrated that the frequency range of the enhancement effect narrows with the decrease of the electron mean free path, l, and at l ⩽ 1 nm electron heating is observed in the whole frequency range. Dependences of frequency boundaries on l are explained by taking into account strong electron-electron interaction in impure metals.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1687
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Author Gershenzon, E. M.; Gol'tsman, G. N.; Potapov, V. D.; Sergeev, A. V.
Title Restriction of microwave enhancement of superconductivity in impure superconductors due to electron-electron interaction Type Journal Article
Year 1991 Publication Phys. B Condens. Mat. Abbreviated Journal Phys. B Condens. Mat.
Volume 169 Issue 1-4 Pages 629-630
Keywords impure superconductors
Abstract (down) Transition from microwave enhancement of supercurrent to superconductivity suppression is investigated in impure superconductors. It is demonstrated that frequency range of enhancement effect narrows with the decrease of electron mean free path, ℓ, and at ℓ⩽1nm electron heating is observed in the whole frequency range. Dependences of frequency boundaries on ℓ are explained by taking into account strong electron-electron interaction in impure metals.
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 0921-4526 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1682
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Author Gol'tsman, G. N.; Kouminov, P.; Goghidze, I.; Gershenzon, E. M.
Title Nonequilibrium kinetic inductive response of YBaCuO thin films to low-power laser pulses Type Journal Article
Year 1994 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.
Volume 235-240 Issue Pages 1979-1980
Keywords YBCO HTS KID
Abstract (down) Transient non-equilibrium kinetic inductive voltage response of YBaCuO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 μm and 1.5 μm wavelength has been revealed. By increasing the sensitivity of 100 ps resolution time registration system and diminishing light intensity (fluence 0.1-1 μJ2/cm2) and transport current (density j≤105 A/cm2) we observed a perculiar bipolar signal form with nearly equal amplitudes of each sign. The integration of the kinetic inductive response over time gives the result which is qualitatively of the same form as the response in the resistive and normal states: nonequilibrium picosecond scale component followed by bolometric nanosecond. Nonequilibrium response is interpreted as suppression of order parameter by excess of quasiparticles followed by a change in resistance in the resistive state and kinetic inductance in superconductive state.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1634
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Author Lobanov, Y.; Shcherbatenko, M.; Finkel, M.; Maslennikov, S.; Semenov, A.; Voronov, B. M.; Rodin, A. V.; Klapwijk, T. M.; Gol'tsman, G. N.
Title NbN hot-electron-bolometer mixer for operation in the near-IR frequency range Type Journal Article
Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 25 Issue 3 Pages 2300704 (1 to 4)
Keywords HEB mixer, IR, optical antenna
Abstract (down) Traditionally, hot-electron-bolometer (HEB) mixers are employed for THz and “super-THz” heterodyne detection. To explore the near-IR spectral range, we propose a fiber-coupled NbN film based HEB mixer. To enhance the incident-light absorption, a quasi-antenna consisting of a set of parallel stripes of gold is used. To study the antenna effect on the mixer performance, we have experimentally studied a set of devices with different size of the Au stripe and spacing between the neighboring stripes. With use of the well-known isotherm technique we have estimated the absorption efficiency of the mixer, and the maximum efficiency has been observed for devices with the smallest pitch of the alternating NbN and NbN-Au stripes. Also, a proper alignment of the incident Eâƒ<2014>-field with respect to the stripes allows us to improve the coupling further. Studying IV-characteristics of the mixer under differently-aligned Eâƒ<2014>-field of the incident radiation, we have noticed a difference in their shape. This observation suggests that a difference exists in the way the two waves with orthogonal polarizations parallel and perpendicular Eâƒ<2014>-field to the stripes heat the electrons in the HEB mixer. The latter results in a variation in the electron temperature distribution over the HEB device irradiated by the two waves.
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Notes Approved no
Call Number Serial 952
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Author Lobanov, Y.; Shcherbatenko, M.; Semenov, A.; Kovalyuk, V.; Kahl, O.; Ferrari, S.; Korneev, A.; Ozhegov, R.; Kaurova, N.; Voronov, B. M.; Pernice, W. H. P.; Gol'tsman, G. N.
Title Superconducting nanowire single photon detector for coherent detection of weak signals Type Journal Article
Year 2017 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 27 Issue 4 Pages 1-5
Keywords NbN SSPD mixer, SNSPD, nanophotonic waveguide
Abstract (down) Traditional photon detectors are operated in the direct detection mode, counting incident photons with a known quantum efficiency. Here, we have investigated a superconducting nanowire single photon detector (SNSPD) operated as a photon counting mixer at telecommunication wavelength around 1.5 μm. This regime of operation combines excellent sensitivity of a photon counting detector with excellent spectral resolution given by the heterodyne technique. Advantageously, we have found that low local oscillator (LO) power of the order of hundreds of femtowatts to a few picowatts is sufficient for clear observation of the incident test signal with the sensitivity approaching the quantum limit. With further optimization, the required LO power could be significantly reduced, which is promising for many practical applications, such as the development of receiver matrices or recording ultralow signals at a level of less-than-one-photon per second. In addition to a traditional NbN-based SNSPD operated with normal incidence coupling, we also use detectors with a travelling wave geometry, where a NbN nanowire is placed on the top of a Si 3 N 4 nanophotonic waveguide. This approach is fully scalable and a large number of devices could be integrated on a single chip.
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 1206
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Author Shcheslavskiy, V.; Morozov, P.; Divochiy, A.; Vakhtomin, Yu.; Smirnov, K.; Becker, W.
Title Ultrafast time measurements by time-correlated single photon counting coupled with superconducting single photon detector Type Journal Article
Year 2016 Publication Rev. Sci. Instrum. Abbreviated Journal
Volume 87 Issue Pages 053117 (1 to 5)
Keywords SSPD, SNSPD, TCSPC, jitter
Abstract (down) Time resolution is one of the main characteristics of the single photon detectors besides quantum efficiency and dark count rate. We demonstrate here an ultrafast time-correlated single photon counting (TCSPC) setup consisting of a newly developed single photon counting board SPC-150NX and a superconducting NbN single photon detector with a sensitive area of 7 × 7 μm. The combination delivers a record instrument response function with a full width at half maximum of 17.8 ps and system quantum efficiency ~5% at wavelength of 1560 nm. A calculation of the root mean square value of the timing jitter for channels with counts more than 1% of the peak value yielded about 7.6 ps. The setup has also good timing stability of the detector–TCSPC board.
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Notes Approved no
Call Number Serial 1077
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Author Sidorova, Maria V.; Divochiy, Alexander V.; Vakhtomin, Yury B.; Smirnov, Konstantin V.
Title Ultrafast superconducting single-photon detector with a reduced active area coupled to a tapered lensed single-mode fiber Type Journal Article
Year 2015 Publication J. Nanophoton. Abbreviated Journal
Volume 9 Issue 1 Pages 093051
Keywords SSPD, SNSPD
Abstract (down) This paper presents an ultrafast niobium nitride (NbN) superconducting single-photon detector (SSPD) with an active area of 3×3  μm2 that offers better timing performance metrics than the previous SSPD with an active area of 7×7  μm2. The improved SSPD demonstrates a record timing jitter (<25  ps), an ultrashort recovery time (<2  ns), an extremely low dark count rate, and a high detection efficiency in a wide spectral range from visible part to near infrared. The record parameters were obtained due to the development of a new technique providing effective optical coupling between a detector with a reduced active area and a standard single-mode telecommunication fiber. The advantages of the new approach are experimentally confirmed by taking electro-optical measurements.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1934-2608 ISBN Medium
Area Expedition Conference
Notes 10.1117/1.JNP.9.093051 Approved no
Call Number RPLAB @ sasha @ Serial 1052
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