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Author Mitin, Vladimir; Antipov, Andrei; Sergeev, Andrei; Vagidov, Nizami; Eason, David; Strasser, Gottfried
Title (up) Quantum Dot Infrared Photodetectors: Photoresponse Enhancement Due to Potential Barriers Type Journal Article
Year 2011 Publication Nanoscale Research Letters Abbreviated Journal Nanoscale res lett
Volume 6 Issue 1 Pages 6
Keywords Quantum dots; Infrared detectors; Photoresponse; Doping; Potential barriers; Capture processes
Abstract Potential barriers around quantum dots (QDs) play a key role in kinetics of photoelectrons. These barriers are always created, when electrons from dopants outside QDs fill the dots. Potential barriers suppress the capture processes of photoelectrons and increase the photoresponse. To directly investigate the effect of potential barriers on photoelectron kinetics, we fabricated several QD structures with different positions of dopants and various levels of doping. The potential barriers as a function of doping and dopant positions have been determined using nextnano3 software. We experimentally investigated the photoresponse to IR radiation as a function of the radiation frequency and voltage bias. We also measured the dark current in these QD structures. Our investigations show that the photoresponse increases ~30 times as the height of potential barriers changes from 30 to 130 meV.
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Call Number RPLAB @ gujma @ Serial 712
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Author Verevkin, A.; Slysz, W.; Pearlman, A.; Zhang, J.; Sobolewski, R.; Okunev, O.; Korneev, A.; Kouminov, P.; Smirnov, K.; Chulkova, G.; Gol’tsman, G. N.; Currie, M.
Title (up) Real-time GHz-rate counting of infrared photons using nanostructured NbN superconducting detectors Type Conference Article
Year 2003 Publication CLEO/QELS Abbreviated Journal CLEO/QELS
Volume Issue Pages CThM8
Keywords NbN SSPD; SNSPD; Infrared; Quantum detectors; Detectors; Photon counting; Quantum communications; Quantum cryptography; Single photon detectors; Superconductors
Abstract We demonstrate that our ultrathin, nanometer-width NbN superconducting single-photon detectors are capable of above 1-GHz-frequency, real-time counting of near-infrared photons. The measured system jitter of the detector is below 15 ps.
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Publisher Optical Society of America Place of Publication Editor
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Area Expedition Conference Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference
Notes Approved no
Call Number Serial 1517
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Author Okunev, O.; Chulkova, G.; Milostnaya, I.; Antipov, A.; Smirnov, K.; Morozov, D.; Korneev, A.; Voronov, B.; Gol’tsman, G.; Slysz, W.; Wegrzecki, M.; Bar, J.; Grabiec, P.; Górska, M.; Pearlman, A.; Cross, A.; Kitaygorsky, J.; Sobolewski, R.
Title (up) Registration of infrared single photons by a two-channel receiver based on fiber-coupled superconducting single-photon detectors Type Conference Article
Year 2008 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 7009 Issue Pages 70090V (1 to 8)
Keywords SSPD, SNSPD, single-photon detectors, superconductors, superconducting nanost
Abstract Single-photon detectors (SPDs) are the foundation of all quantum communications (QC) protocols. Among different classes of SPDs currently studied, NbN superconducting SPDs (SSPDs) are established as the best devices for ultrafast counting of single photons in the infrared (IR) wavelength range. The SSPDs are nanostructured, 100 μm2 in total area, superconducting meanders, patterned by electron lithography in ultra-thin NbN films. Their operation has been explained within a phenomenological hot-electron photoresponse model. We present the design and performance of a novel, two-channel SPD receiver, based on two fiber-coupled NbN SSPDs. The receivers have been developed for fiber-based QC systems, operational at 1.3 μm and 1.55 μm telecommunication wavelengths. They operate in the temperature range from 4.2 K to 2 K, in which the NbN SSPDs exhibit their best performance. The receiver unit has been designed as a cryostat insert, placed inside a standard liquid-heliumstorage dewar. The input of the receiver consists of a pair of single-mode optical fibers, equipped with the standard FC connectors and kept at room temperature. Coupling between the SSPD and the fiber is achieved using a specially designed, precise micromechanical holder that places the fiber directly on top of the SSPD nanostructure. Our receivers achieve the quantum efficiency of up to 7% for near-IR photons, with the coupling efficiency of about 30%. The response time was measured to be < 1.5 ns and it was limited by our read-out electronics. The jitter of fiber-coupled SSPDs is < 35 ps and their dark-count rate is below 1s-1. The presented performance parameters show that our single-photon receivers are fully applicable for quantum correlation-type QC systems, including practical quantum cryptography.
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Publisher SPIE Place of Publication Editor Sukhoivanov, I.A.; Svich, V.A.; Shmaliy, Y.S.
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Call Number Serial 1413
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Author Gayduchenko, I.; Kardakova, A.; Fedorov, G.; Voronov, B.; Finkel, M.; Jiménez, D.; Morozov, S.; Presniakov, M.; Goltsman, G.
Title (up) Response of asymmetric carbon nanotube network devices to sub-terahertz and terahertz radiation Type Journal Article
Year 2015 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 118 Issue 19 Pages 194303
Keywords terahertz detectors, asymmetric carbon nanotubes, CNT
Abstract Demand for efficient terahertz radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. It was maintained that photothermoelectric effect under certain conditions results in strong response of such devices to terahertz radiation even at room temperature. In this work, we investigate different mechanisms underlying the response of asymmetric carbon nanotube (CNT) based devices to sub-terahertz and terahertz radiation. Our structures are formed with CNT networks instead of individual CNTs so that effects probed are more generic and not caused by peculiarities of an individual nanoscale object. We conclude that the DC voltage response observed in our structures is not only thermal in origin. So called diode-type response caused by asymmetry of the device IV characteristic turns out to be dominant at room temperature. Quantitative analysis provides further routes for the optimization of the device configuration, which may result in appearance of novel terahertz radiation detectors.
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ISSN 0021-8979 ISBN Medium
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Notes Approved no
Call Number Serial 1169
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Author Gol'tsman, G. N.; Semenov, A. D.; Gousev, Y. P.; Zorin, M. A.; Gogidze, I. G.; Gershenzon, E. M.; Lang, P. T.; Knott, W. J.; Renk, K. F.
Title (up) Sensitive picosecond NbN detector for radiation from millimetre wavelengths to visible light Type Journal Article
Year 1991 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.
Volume 4 Issue 9 Pages 453-456
Keywords NbN HEB detectors
Abstract The authors report on the application of a broad-band NbN film detector which has high sensitivity and picosecond response time for detection of radiation from millimetre wavelengths to visible light. From a study of amplitude modulated radiation of backward-wave tubes and picosecond pulses from gas and solid state lasers at wavelengths between 2 mm and 0.53 mu m, they found a detectivity of 1010 W-1 cm Hz-1/2 and a response time of less than 50 ps at T=10 K. The characteristics were provided by using a 150 AA thick NbN film patterned into a structure of micron strips. According to the proposed detection mechanism, namely electron heating, they expect an intrinsic response time of approximately 20 ps at the same temperature.
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Series Editor Series Title Abbreviated Series Title
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ISSN 0953-2048 ISBN Medium
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Notes Approved no
Call Number Serial 242
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