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Schubert J, Semenov A, Hübers H-W, Gol'tsman G, Schwaab G, Voronov B, et al. Broad-band terahertz NbN hot-electron bolometric mixer. In: Inst. Phys. Conf. Vol 167.; 1999. p. 663–6.
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Gershenzon EM, Gol'tsman GN, Elantiev AI, Karasik BS, Potoskuev SE. Intense electromagnetic radiation heating of electrons of a superconductor in the resistive state. Sov J Low Temp Phys. 1988;14(7):414–20.
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Gershenzon EM, Gol'tsman GN, Elant'ev AI, Karasik BS, Potoskuev SE. Intense electromagnetic radiation heating of superconductor electrons in resistive state. Fizika Nizkikh Temperatur. 1988;14(7):753–63.
Abstract: An experimental study is made of the effect of intense radiation in the millimeter and submillimeter ranges on thin and narrow Nb films in the resistive state. It is found that the excess resistance resulting from radiation and the dependence of its relaxation time on radiation intensity and transport current can be explained in terms of the effect of electron heating. Quantitative agreement is obtained between the experimental data and a homogeneous electron heating model.
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Smirnov KV, Vakhtomin YB, Divochiy AV, Ozhegov RV, Pentin IV, Gol'tsman GN. Infrared and terahertz detectors on basis of superconducting nanostructures. In: IEEE, editor. Microwave and Telecom. Technol. (CriMiCo), 20th Int. Crimean Conf.; 2010. p. 823–4.
Abstract: Results of development of single-photon receiving systems of visible, infrared and terahertz range based on thin-film superconducting nanostructures are presented. The receiving systems are produced on the basis of superconducting nanostructures, which function by means of hot-electron phenomena.
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Kawamura JH, Tong C-YE, Blundell R, Cosmo Papa D, Hunter TR, Gol'tsman G, et al. An 800 GHz NbN phonon-cooled hot-electron bolometer mixer receiver. IEEE Trans Appl Supercond. 1999;9(2):3753–6.
Abstract: We describe a heterodyne receiver developed for astronomical applications to operate in the 350 /spl mu/m atmospheric window. The waveguide receiver employs a superconductive NbN phonon-cooled hot-electron bolometer mixer. The double sideband receiver noise temperature closely follows 1 kGHz/sup -1/ across 780-870 GHz, with the intermediate frequency centered at 1.4 GHz. The conversion loss is about 15 dB. The receiver was installed for operation at the University of Arizona/Max Planck Institute for Radio Astronomy Submillimeter Telescope facility. The instrument was successfully used to conduct test observations of a number of celestial sources in a number of astronomically important spectral lines.
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Sobolewski R, Verevkin A, Gol'tsman GN, Lipatov A, Wilsher K. Ultrafast superconducting single-photon optical detectors and their applications. IEEE Trans. Appl. Supercond.. 2003;13(2):1151–7.
Abstract: We present a new class of ultrafast single-photon detectors for counting both visible and infrared photons. The detection mechanism is based on photon-induced hotspot formation, which forces the supercurrent redistribution and leads to the appearance of a transient resistive barrier across an ultrathin, submicrometer-width, superconducting stripe. The devices were fabricated from 3.5-nm- and 10-nm-thick NbN films, patterned into <200-nm-wide stripes in the 4 /spl times/ 4-/spl mu/m/sup 2/ or 10 /spl times/ 10-/spl mu/m/sup 2/ meander-type geometry, and operated at 4.2 K, well below the NbN critical temperature (T/sub c/=10-11 K). Continuous-wave and pulsed-laser optical sources in the 400-nm-to 3500-nm-wavelength range were used to determine the detector performance in the photon-counting mode. Experimental quantum efficiency was found to exponentially depend on the photon wavelength, and for our best, 3.5-nm-thick, 100-/spl mu/m/sup 2/-area devices varied from >10% for 405-nm radiation to 3.5% for 1550-nm photons. The detector response time and jitter were /spl sim/100 ps and 35 ps, respectively, and were acquisition system limited. The dark counts were below 0.01 per second at optimal biasing. In terms of the counting rate, jitter, and dark counts, the NbN single-photon detectors significantly outperform their semiconductor counterparts. Already-identified applications for our devices range from noncontact testing of semiconductor CMOS VLSI circuits to free-space quantum cryptography and communications.
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Baselmans JJA, Hajenius M, Gao JR, Baryshev A, Kooi J, Klapwijk TM, et al. NbN hot electron bolometer mixers: sensitivity, LO power, direct detection and stability. IEEE Trans Appl Supercond. 2005;15(2):484–9.
Abstract: We demonstrate that the performance of NbN lattice cooled hot electron bolometer mixers depends strongly on the interface quality between the bolometer and the contact structure. Both the receiver noise temperature and the gain bandwidth can be improved by a factor of 2 by cleaning the interface and adding an additional superconducting interlayer to the contact pad. Using this we obtain a double sideband receiver noise temperature of 950 K at 2.5 THz and 4.3 K, using a 0.4/spl times/4 /spl mu/m HEB mixer with a spiral antenna. At the same bias point, we obtain an IF gain bandwidth of 6 GHz. To comply with current demands on THz mixers for use in space based receivers we reduce the device size to 0.15/spl times/1 /spl mu/m and use a twin slot antenna. We report measurements of the noise temperature, LO power requirement, stability and the direct detection effect, using a mixer with a 1.6 THz twin slot antenna and a 1.462 THz solid state LO source with calibrated output power.
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Bell M, Kaurova N, Divochiy A, Gol'tsman G, Bird J, Sergeev A, et al. On the nature of resistive transition in disordered superconducting nanowires. IEEE Trans Appl Supercond. 2007;17(2):267–70.
Abstract: Hot-electron single-photon counters based on long superconducting nanowires are starting to become popular in optical and infrared technologies due to their ultimately high sensitivity and very high response speed. We investigate intrinsic fluctuations in long NbN nanowires in the temperature range of 4.2 K-20 K, i.e. above and below the superconducting transition. These fluctuations are responsible for fluctuation resistivity and also determine the noise in practical devices. Measurements of the fluctuation resistivity were performed at low current densities and also in external magnetic fields up to 5 T. Above the BCS critical temperature T co the resistivity is well described by the Aslamazov-Larkin (AL) theory for two-dimensional samples. Below T co the measured resistivity is in excellent agreement with the Langer-Ambegaokar-McCumber-Halperin (LAMH) theory developed for one-dimensional superconductors. Despite that our nanowires of 100 nm width are two-dimensional with respect to the coherence length, our analysis shows that at relatively low current densities the one-dimensional LAMH mechanism based on thermally induced phase slip centers dominates over the two-dimensional mechanism related to unbinding of vortex-antivortex pairs below the Berezinskii-Kosterlitz-Thouless transition.
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Jiang L, Antipov SV, Voronov BM, Gol'tsman GN, Zhang W, Li N, et al. Characterization of the performance of a quasi-optical NbN superconducting HEB mixer. IEEE Trans Appl Supercond. 2007;17(2):395–8.
Abstract: In this paper we focus mainly on the investigation of the performance of a quasi-optical (planar log-spiral antenna) phonon-cooled NbN superconducting hot electron bolometer (HEB) mixer, which is cryogenically cooled by a close-cycled 4-K cryocooler, at 500 and 850 GHz frequency bands. The mixer's noise performance, stability of IF output power, and local oscillator (LO) power requirement are characterized for three NbN superconducting HEB devices of different sizes. The transmission characteristics of Mylar and Zitex films with incidence waves of an elliptical polarization are also examined by measuring the mixer's noise temperature. The lowest receiver noise temperatures (with no corrections) of 750 and 1100 K are measured at 500 and 850 GHz, respectively. Experimental results also demonstrate that the bigger the HEB device is, the higher the stability of IF output power becomes.
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Reiger E, Pan D, Slysz W, Jukna A, Sobolewski R, Dorenbos S, et al. Spectroscopy with nanostructured superconducting single photon detectors. IEEE J Select Topics Quantum Electron. 2007;13(4):934–43.
Abstract: Superconducting single-photon detectors (SSPDs) are nanostructured devices made from ultrathin superconducting films. They are typically operated at liquid helium temperature and exhibit high detection efficiency, in combination with very low dark counts, fast response time, and extremely low timing jitter, within a broad wavelength range from ultraviolet to mid-infrared (up to 6 mu m). SSPDs are very attractive for applications such as fiber-based telecommunication, where single-photon sensitivity and high photon-counting rates are required. We review the current state-of-the-art in the SSPD research and development, and compare the SSPD performance to the best semiconducting avalanche photodiodes and other superconducting photon detectors. Furthermore, we demonstrate that SSPDs can also be successfully implemented in photon-energy-resolving experiments. Our approach is based on the fact that the size of the hotspot, a nonsuperconducting region generated upon photon absorption, is linearly dependent on the photon energy. We introduce a statistical method, where, by measuring the SSPD system detection efficiency at different bias currents, we are able to resolve the wavelength of the incident photons with a resolution of 50 nm.
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