Murphy, A., Semenov, A., Korneev, A., Korneeva, Y., Gol’tsman, G., & Bezryadin, A. (2014). Dark counts initiated by macroscopic quantum tunneling in NbN superconducting photon detectors. arXiv:1410.7689v2 [cond-mat.supr-con].
Abstract: We perform measurements of the switching current distributions of three w = 120 nm wide, 4 nm thick NbN superconducting strips which are used for single-photon detectors. These strips are much wider than the diameter the vortex cores, so they are classified as quasi-two-dimensional (quasi-2D). We discover evidence of macroscopic quantum tunneling by observing the saturation of the standard deviation of the switching distributions at temperatures around 2 K. We analyze our results using the Kurkijarvi-Garg model and find that the escape temperature also saturates at low temperatures, confirming that at sufficiently low temperatures, macroscopic quantum tunneling is possible in quasi-2D strips and can contribute to dark counts observed in single photon detectors.
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Смирнов, К. В. (2009). Создание приборов на сверхпроводниковых счетчиках фотонов и методов диагностики КМОП микросхем, гетероструктур и лазеров на квантовых точках. Министерство образования и науки РФ.
Abstract: Этап №1 (дата окончания: 30.09.2009)
Разработана методика изготовления сверхпроводниковых однофотонных детекторов (SSPD) с монокристаллической структурой пленки сверхмалой толщины. Изготовлены экспериментальные образцы сверхпроводниковых однофотонных детекторов (SSPD). Разработана методика пакетирования сверхпроводникового однофотонного детектора в оптический узел с одномодовым оптоволокном. Изготовлены экспериментальные образцы приемных модулей на основе однофотонных сверхпроводниковых детекторов из NbN-нанопленок.
Этап №2 (дата окончания: 28.10.2009)
Разработаны методы диагностики КМОП микросхем, гетероструктур и лазеров на квантовых точках и методика измерения мощности излучения полупроводниковых лазеров на квантовых точках с использованием сверхпроводниковых однофотонных детекторов (SSPD). Проведена технико-экономическая оценка рыночного потенциала полученных результатов.
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Il'in, K., Siegel, M., Semenov, A., Engel, A., Hübers, H. - W., Hollmann, E., et al. (2004). Thickness dependence of superconducting properties of ultrathin Nb and NbN films. In AKF-Frühjahrstagung.
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Hübers, H. - W., Semenov, A., Richter, H., Smirnov, K., Gol'tsman, G., & Voronov, B. (2002). Phonon cooled far-infrared hot electron bolometer mixer. In NASA/ADS.
Abstract: Heterodyne receivers for applications in astronomy need quantum-limited sensitivity. At frequencies above 1.4 THz superconducting hot electron bolometers (HEB) can be used to achieve this goal. We present results of the development of a quasi-optical phonon-cooled NbN HEB mixer for GREAT, the German heterodyne receiver for SOFIA. Different mixers with logarithmic spiral and double slot feed antennas have been investigated with respect to their noise temperature, conversion loss, linearity and beam pattern at several frequencies between 0.7 THz and 5.2 THz. At 2.5 THz a double sideband noise temperature of 2200 K was achieved. The conversion loss was 16 dB. The response of the mixer was linear up to 400 K load temperature. This performance was verified by measuring an emission line of methanol at 2.5 THz. The results demonstrate that the NbN HEB is very well suited as a mixer for FIR heterodyne receivers.
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Okunev, O., Smirnov, K., Chulkova, G., Korneev, A., Lipatov, A., Gol'tsman, G., et al. (2002). Ultrafast NBN hot-electron single-photon detectors for electronic applications. In Abstracts 8-th IUMRS-ICEM.
Abstract: We present a new, simple to manufacture, single-photon detector (SPD), which can work from ultraviolet to near-infrared wavelengths of optical radiation and combines high speed of operation, high quantum efficiency (QE), and very low dark counts. The devices are superconducting and operate at temperature below 5 K. The physics of operation of our SPD is based on formation of a photon-induced resistive hotspot and subsequent appearance of a transient resistive barrier across an ultrathin and submicron-wide superconductor.
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