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Author Korneev, A.; Matvienko, V.; Minaeva, O.; Milostnaya, I.; Rubtsova, I.; Chulkova, G.; Smirnov, K.; Voronov, V.; Gol’tsman, G.; Slysz, W.; Pearlman, A.; Verevkin, A.; Sobolewski, R.
Title Quantum efficiency and noise equivalent power of nanostructured, NbN, single-photon detectors in the wavelength range from visible to infrared Type Journal Article
Year 2005 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 15 Issue 2 Pages (down) 571-574
Keywords NbN SSPD, SNSPD, QE, NEP
Abstract We present our studies on the quantum efficiency (QE) and the noise equivalent power (NEP) of the latest-generation, nanostructured, superconducting, single-photon detectors (SSPDs) in the wavelength range from 0.5 to 5.6 /spl mu/m, operated at temperatures in the 2.0- to 4.2-K range. Our detectors are designed as 4-nm-thick and 100-nm-wide NbN meander-shaped stripes, patterned by electron-beam lithography and cover a 10/spl times/10-/spl mu/m/sup 2/ active area. The best-achieved QE at 2.0 K for 1.55-/spl mu/m photons is 17%, and QE for 1.3-/spl mu/m infrared photons reaches its saturation value of /spl sim/30%. The SSPD NEP at 2.0 K is as low as 5/spl times/10/sup -21/ W/Hz/sup -1/2/. Our nanostructured SSPDs, operated at 2.0 K, significantly outperform their semiconducting counterparts, and, together with their GHz counting rate and picosecond timing jitter, they are devices-of-choice for practical quantum key distribution systems and free-space (even interplanetary) quantum optical communications.
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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 1558-2515 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1467
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Author Verevkin, A. A.; Ptitsina, N. G.; Chulcova, G. M.; Gol'tsman, G. N.; Gershenzon, E. M.; Yngvesson, K. S.
Title Direct measurements of energy relaxation time of electrons in AlGaAs/GaAs heterostructures under quasi-equilibrium conditions Type Journal Article
Year 1996 Publication Surface Science Abbreviated Journal Surface Science
Volume 361-362 Issue Pages (down) 569-573
Keywords 2DEG, AlGaAs/GaAs heterostructures
Abstract For the first time, results are presented of a direct measurement of the energy relaxation time τε of 2D electrons in an AlGaAs/GaAs heterojunction at T = 1 and 5–20 K. A weak temperature dependence of τε for the T > 4K range and a linear temperature dependence of the reciprocal of τε for T < 4K have been observed. The linear dependence τε−1 ≈ T in the Bloch-Gruneisen regime is direct evidence of the predominance of the piezo-electric mechanism of electron-phonon interaction in non-elastic electron scattering processes. The values of τε in this regime are in very good agreement with the results of the Karpus theory. At higher temperatures, where the deformation-potential scattering becomes noticeable, a substantial disagreement between the experimental data and the theoretical results is observed.
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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 0039-6028 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1609
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Author Verevkin, A. A.; Ptitsina, N. G.; Smirnov, K. V.; Voronov, B. M.; Gol’tsman, G. N.; Gershenson, E. M.; Yngvesson, K. S.
Title Multiple Andreev reflection in hybrid AlGaAs/GaAs structures with superconducting NbN contacts Type Journal Article
Year 1999 Publication Semicond. Abbreviated Journal Semicond.
Volume 33 Issue 5 Pages (down) 551-554
Keywords 2DEG, AlGaAs/GaAs heterostructures
Abstract The conductivity of hybrid microstructures with superconducting contacts made of niobium nitride to a semiconductor with a two-dimensional electron gas in a AlGaAs/GaAs heterostructure has been investigated. Distinctive features of the behavior of the conductivity indicate the presence of multiple Andreev reflection at scattering centers in the normal region near the superconductor-semiconductor boundary.
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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 1063-7826 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1571
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Author Kitaygorsky, J.; Zhang, J.; Verevkin, A.; Sergeev, A.; Korneev, A.; Matvienko, V.; Kouminov, P.; Smirnov, K.; Voronov, B.; Gol'tsman, G.; Sobolewski, R.
Title Origin of dark counts in nanostructured NbN single-photon detectors Type Journal Article
Year 2005 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 15 Issue 2 Pages (down) 545-548
Keywords SSPD dark counts, SNSPD, dark counts rate
Abstract We present our study of dark counts in ultrathin (3.5 to 10 nm thick), narrow (120 to 170 nm wide) NbN superconducting stripes of different lengths. In experiments, where the stripe was completely isolated from the outside world and kept at temperature below the critical temperature Tc, we detected subnanosecond electrical pulses associated with the spontaneous appearance of the temporal resistive state. The resistive state manifested itself as generation of phase-slip centers (PSCs) in our two-dimensional superconducting stripes. Our analysis shows that not far from Tc, PSCs have a thermally activated nature. At lowest temperatures, far below Tc, they are created by quantum fluctuations.
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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 1057
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Author Schwaab, G. W.; Hübers, H.-W.; Schubert, J.; Erichsen, Patrik; Gol'tsman, G.; Semenov, A.; Verevkin, A.; Cherednichenko, S.; Gershenzon, E.
Title A high resolution spectrometer for the investigation of molecular structures in the THZ range Type Conference Article
Year 1999 Publication Proc. 10th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 10th Int. Symp. Space Terahertz Technol.
Volume Issue Pages (down) 530-538
Keywords antireflection coatings, dielectric mirrors
Abstract A status report on the design study of a novel tunable far-infrared (TuFTR) spectrometer for the investigation of the structure of weakly bound molecular complexes is given. The goal is a sensitive TuFIR spectrometer with full frequency coverage from 1-6 THz. To hit the goal, advanced sources (e.g. p-Ge lasers) and detectors (e.g. superconducting hot electron bolometric (HEB) mixers) shall be employed to extend the technique of cavity ringdown spectroscopy, that is currently used at optical and infrared frequencies to the FIR spectral range. Critical for such a system are high-Q resonators that still allow good optical coupling, and wideband antireflection coatings to increase detector sensitivity and decrease optical path losses. 2 nd order effective media theory and an iterative multilayer algorithm have been employed to design wideband antireflection coatings for dielectrics with large dielectric constants like Ge or Si. Taking into account 6 layers, for Si bandwidths of 100% of the center frequency could be obtained with power reflectivities below 1% for both polarizations simultaneously. Wideband dielectric mirrors including absorption losses were also studied yielding a bandwidth of about 50% with reflectivities larger than 99.5%.
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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 1577
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