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Lobanov, Y. V., Vakhtomin, Y. B., Pentin, I. V., Khabibullin, R. A., Shchavruk, N. V., Smirnov, K. V., et al. (2018). Characterization of the THz quantum cascade laser using fast superconducting hot electron bolometer. EPJ Web Conf., 195, 04004 (1 to 2).
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Korneev, A., Kovalyuk, V., An, P., Golikov, A., Zubkova, E., Ferrari, S., et al. (2018). Superconducting single-photon detector for integrated waveguide spectrometer. In EPJ Web Conf. (Vol. 190, 04009).
Abstract: We present our recent achievements in the development of an on-chip spectrometer consisting of arrayed waveguide grating made of Si3N4 waveguides and NbN superconducting single-photon detector.
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Korneeva, Y., Vodolazov, D., Florya, I., Manova, N., Smirnov, E., Korneev, A., et al. (2018). Single photon detection in micron scale NbN and α-MoSi superconducting strips. In EPJ Web Conf. (Vol. 190, 04010 (1 to 2)).
Abstract: We experimentally demonstrate the single photon detection in straight micrometer-wide NbN and α-MoSi bridges. Width of the bridges is 2 µm, while the wavelength of the photon changes from 408 to 1550 nm and critical current exceeds 50% of the depairing current. Obtained results offer the alternative route for design of detectors without resonator and meander structure and indirectly confirm vortex assisted mechanism of single photon detection.
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Goltsman, G., Naumov, A. V., Gladush, M. G., & Karimullin, K. R. (2018). Quantum photonic integrated circuits with waveguide integrated superconducting nanowire single-photon detectors. In EPJ Web Conf. (Vol. 190, 02004 (1 to 2)).
Abstract: We show the design, a history of development as well as the most successful and promising approaches for QPICs realization based on hybrid nanophotonic-superconducting devices, where one of the key elements of such a circuit is a waveguide integrated superconducting single-photon detector (WSSPD). The potential of integration with fluorescent molecules is discussed also.
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Bandurin, D. A., Gayduchenko, I., Cao, Y., Moskotin, M., Principi, A., Grigorieva, I. V., et al. (2018). Dual origin of room temperature sub-terahertz photoresponse in graphene field effect transistors. Appl. Phys. Lett., 112(14), 141101 (1 to 5).
Abstract: Graphene is considered as a promising platform for detectors of high-frequency radiation up to the terahertz (THz) range due to its superior electron mobility. Previously, it has been shown that graphene field effect transistors (FETs) exhibit room temperature broadband photoresponse to incoming THz radiation, thanks to the thermoelectric and/or plasma wave rectification. Both effects exhibit similar functional dependences on the gate voltage, and therefore, it was difficult to disentangle these contributions in previous studies. In this letter, we report on combined experimental and theoretical studies of sub-THz response in graphene field-effect transistors analyzed at different temperatures. This temperature-dependent study allowed us to reveal the role of the photo-thermoelectric effect, p-n junction rectification, and plasmonic rectification in the sub-THz photoresponse of graphene FETs.
D.A.B. acknowledges the Leverhulme Trust for financial support. The work of D.S. was supported by Grant No. 16-19-10557 of the Russian Scientific Foundation (theoretical model). G.F., I.G., M.M., and G.G. acknowledge the Russian Science Foundation [Grant No. 14-19-01308 (MIET, cryostat upgrade) and Grant No. 17-72-30036, (MSPU, photoresponse measurements), the Ministry of Education and Science of the Russian Federation (Contract No. 14.B25.31.0007 (device fabrication) and Task No. 3.7328.2017/LS (NEP analyses)] and the Russian Foundation for Basic Research [Grant No. 15-02-07841 (device design)]. The authors are grateful to Professor M. S. Shur for helpful discussions.
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Sidorova, M., Semenov, A., Hübers, H. - W., Kuzmin, A., Doerner, S., Ilin, K., et al. (2018). Timing jitter in photon detection by straight superconducting nanowires: Effect of magnetic field and photon flux. Phys. Rev. B, 98(13), 134504 (1 to 14).
Abstract: We studied the effects of the external magnetic field and photon flux on timing jitter in photon detection by straight superconducting NbN nanowires. At two wavelengths 800 and 1560 nm, statistical distribution in the appearance times of photon counts exhibits Gaussian shape at small times and an exponential tail at large times. The characteristic exponential time is larger for photons with smaller energy and increases with external magnetic field while variations in the Gaussian part of the distribution are less pronounced. Increasing photon flux drives the nanowire from the discrete quantum detection regime to the uniform bolometric regime that averages out fluctuations of the total number of nonequilibrium electrons created by the photon and drastically reduces jitter. The difference between standard deviations of Gaussian parts of distributions for these two regimes provides the measure for the strength of electron-number fluctuations; it increases with the photon energy. We show that the two-dimensional hot-spot detection model explains qualitatively the effect of magnetic field.
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Sidorova, M. V., Kozorezov, A. G., Semenov, A. V., Korneeva, Y. P., Mikhailov, M. Y., Devizenko, A. Y., et al. (2018). Nonbolometric bottleneck in electron-phonon relaxation in ultrathin WSi films. Phys. Rev. B, 97(18), 184512 (1 to 13).
Abstract: We developed the model of the internal phonon bottleneck to describe the energy exchange between the acoustically soft ultrathin metal film and acoustically rigid substrate. Discriminating phonons in the film into two groups, escaping and nonescaping, we show that electrons and nonescaping phonons may form a unified subsystem, which is cooled down only due to interactions with escaping phonons, either due to direct phonon conversion or indirect sequential interaction with an electronic system. Using an amplitude-modulated absorption of the sub-THz radiation technique, we studied electron-phonon relaxation in ultrathin disordered films of tungsten silicide. We found an experimental proof of the internal phonon bottleneck. The experiment and simulation based on the proposed model agree well, resulting in τe−ph∼140–190 ps at TC=3.4K, supporting the results of earlier measurements by independent techniques.
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Eletskii, A. V., Sarychev, A. K., Boginskaya, I. A., Bocharov, G. S., Gaiduchenko, I. A., Egin, M. S., et al. (2018). Amplification of a Raman scattering signal by carbon nanotubes. Dokl. Phys., 63(12), 496–498.
Abstract: The effect of Raman scattering (RLS) signal amplification by carbon nanotubes (CNTs) was studied. Single-layered nanotubes were synthesized by the chemical vapor deposition (CVD) method using methane as a carbon-containing gas. The object of study used was water, the Raman spectrum of which is rather well known. Amplification of the Raman scattering signal by several hundred percent was attained in our work. The maximum amplification of a Raman scattering signal was shown to be achieved at an optimal density of nanotubes on a substrate. This effect was due to the scattering and screening of plasmons excited in CNTs by neighboring nanotubes. The amplification mechanism and the possibilities of optimization for this effect were discussed on the basis of the theory of plasmon resonance in carbon nanotubes.
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Tretyakov, I. V., Anfertyev, V. A., Revin, L. S., Kaurova, N. S., Voronov, B. M., Vaks, V. L., et al. (2018). Sensitivity and resolution of a heterodyne receiver based on the NbN HEB mixer with a quantum-cascade laser as a local oscillator. Radiophys. Quant. Electron., 60(12), 988–992.
Abstract: We present the results of experimental studies of the basic characteristics and operation features of a terahertz heterodyne detector based on the superconducting NbN HEB mixer and a quantum cascade laser as a local oscillator operating at a frequency of 2.02 THz. The measured noise temperature of such a mixer amounted to 1500 K. The spectral resolution of the detector is determined by the width of the local-oscillator spectral line whose measured value does not exceed 1 MHz. The quantum-cascade laser could be linearly tuned with respect to frequency with the coefficient 7.2 MHz/mA within the limits of the current oscillation bandwidth.
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Florya, I. N., Korneeva, Y. P., Mikhailov, M. Y., Devizenko, A. Y., Korneev, A. A., & Goltsman, G. N. (2018). Photon counting statistics of superconducting single-photon detectors made of a three-layer WSi film. Low Temp. Phys., 44(3), 221–225.
Abstract: Superconducting nanowire single-photon detectors (SNSPD) are used in quantum optics when record-breaking time resolution, high speed, and exceptionally low levels of dark counts (false readings) are required. Their detection efficiency is limited, however, by the absorption coefficient of the ultrathin superconducting film for the detected radiation. One possible way of increasing the detector absorption without limiting its broadband response is to make a detector in the form of several vertically stacked layers and connect them in parallel. For the first time we have studied single-photon detection in a multilayer structure consisting of three superconducting layers of amorphous tungsten silicide (WSi) separated by thin layers of amorphous silicon. Two operating modes of the detector are illustrated: an avalanche regime and an arm-trigger regime. A shift in these modes occurs at currents of ∼0.5–0.6 times the critical current of the detector.
This work was supported by technical task No. 88 for scientific research at the National Research University “Higher School of Economics,” Grant No. 14.V25.31.0007 from the Ministry of Education and Science of Russia, and the work of G. N. Goltsman was supported by task No. 3.7328.2017/VU of the Ministry of Education and Science of Russia.
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