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Pernice, W. H. P., Schuck, C., Minaeva, O., Li, M., Goltsman, G. N., Sergienko, A. V., et al. (2012). High-speed and high-efficiency travelling wave single-photon detectors embedded in nanophotonic circuits. Nat. Commun., 3, 1325 (1 to 10).
Abstract: Ultrafast, high-efficiency single-photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. However, imperfect modal matching and finite photon absorption rates have usually limited their maximum attainable detection efficiency. Here we demonstrate superconducting nanowire detectors atop nanophotonic waveguides, which enable a drastic increase of the absorption length for incoming photons. This allows us to achieve high on-chip single-photon detection efficiency up to 91% at telecom wavelengths, repeatable across several fabricated chips. We also observe remarkably low dark count rates without significant compromise of the on-chip detection efficiency. The detectors are fully embedded in scalable silicon photonic circuits and provide ultrashort timing jitter of 18 ps. Exploiting this high temporal resolution, we demonstrate ballistic photon transport in silicon ring resonators. Our direct implementation of a high-performance single-photon detector on chip overcomes a major barrier in integrated quantum photonics.
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Averkin, A. S., Shishkin, A. G., Chichkov, V. I., Voronov, B. M., Goltsman, G. N., Karpov, A., et al. (2014). Tunable frequency-selective surface based on superconducting split-ring resonators. In 8th Metamaterials.
Abstract: We study a possibility to use the 2D superconducting metamaterial as a tunable frequency-selective surface (FSS). The proposed FSS is made of sub-wavelength size (l/14) metamaterial unit cells, where a split-ring resonator is embedded in a small iris aperture in a metal plane. The split-ring resonator is made of NbN film, and its resonance frequency is tuned by the temperature of the sample, changing the kinetic inductance of NbN film. The Ansoft HFSS simulation predicts the FSS tuning range of about 10-20 %. The developed superconducting FSS may be used as a tunable band-pass filter or modulator.
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Gershenzon, E. M., Goltsman, G. N., & Orlov, L. (1976). Investigation of population and ionization of donor excited states in Ge. In Physics of Semiconductors (pp. 631–634). North-Holland Publishing Co.
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Ryabchun, S. A., Tretyakov, I. V., Finkel, M. I., Maslennikov, S. N., Kaurova, N. S., Seleznev, V. A., et al. (2008). Fabrication and characterisation of NbN HEB mixers with in situ gold contacts. In Proc. 19th Int. Symp. Space Terahertz Technol. (pp. 62–67). Groningen, Netherlands.
Abstract: We present our recent results of the fabrication and testing of NbN hot-electron bolometer mixers with in situ gold contacts. An intermediate frequency bandwidth of about 6 GHz has been measured for the mixers made of a 3.5-nm NbN film on a plane Si substrate with in situ gold contacts, compared to 3.5 GHz for devices made of the same film with ex situ gold contacts. The increase in the intermediate frequency bandwidth is attributed to additional diffusion cooling through the improved contacts, which is further supported by the its dependence on the bridge length: intermediate frequency bandwidths of 3.5 GHz and 6 GHz have been measured for devices with lengths of 0.35 μm and 0.16 μm respectively at a local oscillator frequency of 300 GHz near the superconducting transition. At a local oscillator frequency of 2.5 THz the receiver has offered a DSB noise temperature of 950 K. When compared to the previous result of 1300 K obtained at the same local oscillator frequency for devices fabricated with an ex situ route, such a low value of the noise temperature may also be attributed to the improved gold contacts.
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Gershenzon, E. M., Goltsman, G. N., Semenov, A. D., & Sergeev, A. V. (1989). Limiting characteristic of fast superconducting bolometers. Sov. Phys.-Tech. Phys., 34, 195–199.
Abstract: Теоретически и экспериментально исследовано физическое ограничение быстродействия сверхпроводящего болометра. Показано, что минимальная постоянная времени реализуется в условиях электронного разогрева и определяется процессом неупругого электрон-фонон- ного взаимодействия. Сформулированы требования кконструкции «электронного болометра» для достижения предельной чувствительности. Проведено сравнение характеристик электронного болометра и обычных болометров различных типов.
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Gershenzon, E. M., Gershenzon, M. E., Goltsman, G. N., Semenov, A. D., & Sergeev, A. V. (1991). Wide-band highspeed Nb and YBaCuO detectors. IEEE Trans. Magn., 27(2), 2836–2839.
Abstract: The physical limitations on the response time and the nature of nonequilibrium detection of radiation were investigated for Nb and YBCO film in a wide spectral range from millimeter to near-infrared wavelengths. In the case of ideal heat removal from the film, the detection mechanism is connected with an electron heating effect which is not selective over a wide spectral interval. For Nb, the dependence of the response time on the electron mean free path l and temperature T is tau varies as T/sup -2/l/sup -1/. The values of detectivity D* and tau are 3*10/sup 11/ W/sup -1/ Hz/sup 1/2/ cm and 5*10/sup -9/ s at T=1.6 K, respectively. For YBCO film the tau value of 1-2 ps at T=77 K was obtained; the NEP value of 3*10/sup -11/ W-Hz/sup -1/2/ can be obtained at T=77 K in the case of the optimal film matching to the radiation.
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Gershenzon, E. M., Gershenzon, M. E., Goltsman, G. N., Lulkin, A., Semenov, A. D., & Sergeev, A. V. (1990). Electron-phonon interaction in ultrathin Nb films. Sov. Phys. JETP, 70(3), 505–511.
Abstract: A study was made of the heating of electrons in normal resistive states of superconducting thin Nb films. The directly determined relaxation time of the resistance of a sample and the rise of the electron temperature were used to find the electron-phonon interaction time rep,, The dependence of rep, on the mean free path of electrons re,, a 1-'demonstrated, in agreement with the theoretical predictions, that the contribution of the inelastic scattering of electrons by impurities to the energy relaxation process decreased at low temperatures and the observed temperature dependence rep, a T 2 was due to a modification of the phonon spectrum in thin fllms.
1. Much new information on the electron-phonon interaction time?;,, in thin films of normal metals and superconductors has been published recently. This information has been obtained mainly as a result of two types of measurement. One includes experiments on weak electron localization investigated by the method of quantum interference corrections to the conductivity of disordered conductors, which can be used to find the relaxation time T, of the phase of the electron wave function. In the absence of the scattering of electrons by paramagnetic impurities the relaxation time T, is associated with the most effective process of energy relaxation: T;= TL+ rep;, where T,, is the electronelectron relaxation time. At low temperatures, when the dependence T; a T is exhibited by thin disordered films, the dominant channel is that of the electron-electron relaxation and there is a lower limit to the temperature range in which rep, can be investigated.
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Tikhonov, V. V., Boyarskii, D. A., Polyakova, O. N., Dzardanov, A. L., & Goltsman, G. N. (2010). Radiophysical and dielectric properties of ore minerals in 12--145 GHz frequency range. PIER B, 25, 349–367.
Abstract: The paper discusses a retrieval technique of complex permittivity of ore minerals in frequency ranges of 12--38 GHz and 77--145 GHz. The method is based on measuring frequency dependencies of transmissivity and reflectivity of plate-parallel mineral samples. In the 12--38 GHz range, the measurements were conducted using a panoramic standing wave ratio and attenuation meter. In the 77--145 GHz range, frequency dependencies of transmissivity and reflectivity were obtained using millimeter-band spectrometer with backward-wave oscillators. The real and imaginary parts of complex permittivity of a mineral were determined solving an equation system for frequency dependencies of transmissivity and reflectivity of an absorbing layer located between two dielectric media. In the course of the work, minerals that are primary ores in iron, zinc, copper and titanium mining were investigated: magnetite, hematite, sphalerite, chalcopyrite, pyrite, and ilmenite.
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Pernice, W., Schuck, C., Li, M., Goltsman, G. N., Sergienko, A. V., & Tang, H. X. (2011). High speed travelling wave single-photon detectors with near-unity quantum efficiency. arXiv, , 1–14.
Abstract: Ultrafast, high quantum efficiency single photon detectors are among the most sought-after elements in modern quantum optics and quantum communication. Close-to-unity photon detection efficiency is essential for scalable measurement-based quantum computation, quantum key distribution, and loophole-free Bell experiments. However, imperfect modal matching and finite photon absorption rates have usually limited the maximum attainable detection efficiency of single photon detectors. Here we demonstrate a superconducting nanowire detector atop nanophotonic waveguides and achieve single photon detection efficiency up to 94% at telecom wavelengths. Our detectors are fully embedded in a scalable, low loss silicon photonic circuit and provide ultrashort timing jitter of 18ps at multi-GHz detection rates. Exploiting this high temporal resolution we demonstrate ballistic photon transport in silicon ring resonators. The direct implementation of such a detector with high quantum efficiency, high detection speed and low jitter time on chip overcomes a major barrier in integrated quantum photonics.
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Shangina, E. L., Smirnov, K. V., Morozov, D. V., Kovalyuk, V. V., Goltsman, G. N., Verevkin, A. A., et al. (2011). Concentration dependence of energy relaxation time in AlGaAs/GaAs heterojunctions: direct measurements. Semicond. Sci. Technol., 26(2), 025013.
Abstract: We present measurements of the energy relaxation time, τε, of electrons in a single heterojunction in a quasi-equilibrium state using microwave time-resolved spectroscopy at 4.2 K. We find the relaxation time has a power-law dependence on the carrier density of the two-dimensional electron gas, τε∝nγs with γ = 0.40 ± 0.02 for values of the carrier density, ns, from 1.6 × 1011 to 6.6 × 1011cm−2. The results are in good agreement with predictions taking into account the scattering of the carriers by both piezoelectric and deformation potential acoustic phonons. We compare these results with indirect measurements of the energy relaxation time from energy loss measurements involving Joule heating of the electron gas.
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