|
|
Шангина, Е. Л., Смирнов, К. В., Морозов, Д. В., Ковалюк, В. В., Гольцман, Г. Н., Веревкин, А. А., et al. (2010). Полоса и потери преобразования полупроводникового смесителя с фононным каналом охлаждения двумерных электронов. Физика и техника полупроводников, 44(11), 1475–1478.
Abstract: Методом субмиллиметровой спектроскопии с высоким временным разрешением измерены температурная и концентрационная зависимости полосы преобразования смесителей терагерцового диапазона AlGaAs/GaAs на разогреве двумерных электронов с фононным каналом их охлаждения. Полоса преобразования на уровне 3 дБ (f3 dB) при 4.2 K при изменении концентрации ns варьируется в пределах 150-250 МГц в соответствии со степенным законом f3 dB propto ns-0.5, что соответствует доминирующему механизму рассеяния на пьезоэлектрических фононах. Минимальное значение коэффициента потерь преобразования полупроводникового смесителя достигается в структурах с высокой подвижностью носителей mu>3·105 см2/В·с при 4.2 K.
|
|
|
|
Goltsman, G., Korneev, A., Divochiy, A., Minaeva, O., Tarkhov, M., Kaurova, N., et al. (2009). Ultrafast superconducting single-photon detector. J. Modern Opt., 56(15), 1670–1680.
Abstract: The state-of-the-art of the NbN nanowire superconducting single-photon detector technology (SSPD) is presented. The SSPDs exhibit excellent performance at 2 K temperature: 30% quantum efficiency from visible to infrared, negligible dark count rate, single-photon sensitivity up to 5.6 µm. The recent achievements in the development of GHz counting rate devices with photon-number resolving capability is presented.
|
|
|
|
Korneeva, Y. P., Manova, N. N., Dryazgov, M. A., Simonov, N. O., Zolotov, P. I., & Korneev, A. A. (2021). Influence of sheet resistance and strip width on the detection efficiency saturation in micron-wide superconducting strips and large-area meanders. Supercond. Sci. Technol., 34(8), 084001.
Abstract: We report our study of detection efficiency (DE) saturation in wavelength range 400 – 1550 nm for the NbN Superconducting Microstrip Single-Photon Detectors (SMSPD) featuring the strip width up to 3 μm. We observe an expected decrease of the $DE$ saturation plateau with the increase of photon wavelength and decrease of film sheet resistance. At 1.7 K temperature DE saturation can be clearly observed at 1550 nm wavelength in strip with the width up to 2 μm when sheet resistance of the film is above 630Ω/sq. In such strips the length of the saturation plateau almost does not depend on the strip width. We used these films to make meander-shaped detectors with the light sensitive area from 20×20μm2 to a circle 50 μm in diameter. In the latter case, the detector with the strip width of 0.49 μm demonstrates saturation of DE up to 1064 nm wavelength. Although DE at 1310 and 1550 nm is not saturated, it is as high as 60%. The response time is limited by the kinetic inductance and equals to 20 ns(by 1/e decay), timing jitter is 44 ps. When coupled to multi-mode fibre large-area meanders demonstrate significantly higher dark count rate which we attribute to thermal background photons, thus advanced filtering technique would be required for practical applications.
|
|
|
|
Seki, T., Shibata, H., Takesue, H., Tokura, Y., & Imoto, N. (2010). Comparison of timing jitter between NbN superconducting single-photon detector and avalanche photodiode. Phys. C, 470(20), 1534–1537.
Abstract: We report the pulse-to-pulse timing jitter measurement of a niobium nitride (NbN) superconducting single-photon detector (SSPD) and an InGaAs avalanche photodiode (APD) at 1550-nm wavelength. A direct comparison of their timing jitter was performed by using the same experimental configuration to measure both detectors. The measured jitter of the SSPD and the APD are 75 and 84 ps at full-width at half-maximum (FWHM), and 138 and 384 ps at full-width at tenth-maximum (FWTM), respectively. The jitter of the SSPD remains small at FWTM while that of APD is wide. We also estimated the transmission distances and secure key generation rates for fiber-based quantum key distribution (QKD) which uses these detectors. The estimated transmission distances of the APD are 86 km and 107 km with respect to 1 ns and 100 ps time windows, respectively, and those of the SSPD are 125 km and 172 km with respect to 1 ns and 100 ps time windows, respectively. This estimation indicates the SSPDЃfs advantages for QKD compared to the APD.
|
|
|
|
Shah, J., Pinczuk, A., Gossard, A. C., & Wiegmann, W. (1985). Energy-loss rates for hot electrons and holes in GaAs quantum wells. Phys. Rev. Lett., 54, 2045–2048.
Abstract: We report the first direct determination of carrier-energy-loss rates in a semiconductor. These measurements provide fundamental insight into carrier-phonon interactions in semiconductors. Unexpectedly large differences are found in the energy-loss rates for electrons and holes in GaAs/AlGaAs quantum wells. This large difference results from an anomalously low electron-energy-loss rate, which we attribute to the presence of nonequilibrium optical phonons rather than the effects of reduced dimensionality or dynamic screening.
|
|
