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Gershenzon EM, Gol'tsman GN, Semenov AD, Sergeev AV. Mechanism of picosecond response of granular YBaCuO films to electromagnetic radiation. Solid State Communications. 1990;76(4):493–7.
Abstract: The ultrafast mechanisms of radiation detection in granular YBaCuO films are studied in the wide wavelength range from millimeter to near infrared. With the rise of radiation frequency the Josephson detection at the grain boundary weak links is replaced by electron heating into the grains. This change occurs in the submillimeter wavelength range. Electron-phonon relaxation time τeph is determined by direct measurements and analyses quasistationary electron heating. Temperature dependence of τeph at T ≤ 40 K was found to be τeph ∼ T−1. The results show that detectors with the response time of few picoseconds at nitrogen temperature are attainable.
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Men’shchikov EM, Gogidze IG, Sergeev AV, Elant’ev AI, Kuminov PB, Gol’tsman GN, et al. Superconducting fast detector based on the nonequilibrium inductance response of a film of niobium nitride. Tech Phys Lett. 1997;23(6):486–8.
Abstract: A new type of fast detector is proposed, whose operation is based on the variation of the kinetic inductance of a superconducting film caused by nonequilibrium quasiparticles created by the electromagnetic radiation. The speed of the detector is determined by the rate of multiplication of photo-excited quasiparticles, and is nearly independent of the temperature, being less than 1 ps for NbN. Models based on the Owen-Scalapino scheme give a good description of the experimentally determined dependence of the power-voltage sensitivity of the detector on the modulation frequency. The lifetime of the quasiparticles is determined, and it is shown that the reabsorption of nonequilibrium phonons by the condensate has a substantial effect even in ultrathin NbN films 5 nm thick, and results in the maximum possible quantum yield. A low concentration of equilibrium quasiparticles and a high quantum yield result in a detectivity D*=1012 W−1·Hz1/2 at a temperature T=4.2 K and D*=1016 W−1·cm· Hz1/2 at T=1.6 K.
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Gershenzon EM, Gol’tsman GN, Sergeev A, Semenov AD. Picosecond response of YBaCuO films to electromagnetic radiation. In: Gorzkowski W, Gutowski M, Reich A, Szymczak H, editors. Proc. European Conf. High-Tc Thin Films and Single Crystals.; 1990. p. 457–62.
Abstract: Radiation-induced change of the resistance was studied in the resistive state of YBaCuO films. Electron-phonon relaxation time T h was determmed from direct ep measurements and analysis of quasistationary electron heating. Temperature dependence of That TS 40 K was found to – ep be T h.. T'. The resul ts show that ep detectors with the response time of few picosecond at nitrogen temperature can be realized.
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Gershenzon EM, Goltsman GN, Multanovskii VV, Ptitsina NG. Kinetics of submillimeter impurity and exciton photoconduction in Ge. Optics and Spectroscopy. 1982;52(4):454–5.
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Gol'tsman GN, Semenov AD, Gousev YP, Zorin MA, Gogidze IG, Gershenzon EM, et al. Sensitive picosecond NbN detector for radiation from millimetre wavelengths to visible light. Supercond Sci Technol. 1991;4(9):453–6.
Abstract: The authors report on the application of a broad-band NbN film detector which has high sensitivity and picosecond response time for detection of radiation from millimetre wavelengths to visible light. From a study of amplitude modulated radiation of backward-wave tubes and picosecond pulses from gas and solid state lasers at wavelengths between 2 mm and 0.53 mu m, they found a detectivity of 1010 W-1 cm Hz-1/2 and a response time of less than 50 ps at T=10 K. The characteristics were provided by using a 150 AA thick NbN film patterned into a structure of micron strips. According to the proposed detection mechanism, namely electron heating, they expect an intrinsic response time of approximately 20 ps at the same temperature.
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Gershenzon EM, Gol'tsman GN. Effect of electromagnetic radiation on a superconductor in a magnetic field. In: Izv. Akad. Nauk SSSR, Seriya Fizicheskaya. Vol 52.; 1988. p. 449–51.
Abstract: The effect of electromagnetic radiation on thin superconducting films of Nb with a large number of static defects is investigated experimentally for the case where the film is in the resistive state due to an applied magnetic field and transport current. The results obtained are found to be well described by a model of spatially homogeneous electron heating. It is noted that the results obtained here for Nb films are also valid for Al, NbN, and MoRe films.
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Gershenzon EM, Gershenzon ME, Gol'tsman GN, Semenov AD, Sergeev AV. Heating of electrons in a superconductor in the resistive state by electromagnetic radiation. Sov Phys JETP. 1984;59(2):442–50.
Abstract: The effect of heating of electrons relative to phonons is observed and investigated in a superconducting film that is made resistive by current and by an external magnetic field. The effect is manifested by an increase of the film resistance under the influence of the electromagnetic radiation, and is not selective in the frequency band 10^10-10^15 Hz. The independence of the effect of frequency under conditions of strong scattering by static defects is attributed to the decisive role of electron-electron collisions in the distribution function. The experimentally obtained characteristic time of resistance variation near the superconducting transition corresponds to the relaxation time of the order parameter, while at lower temperatures and fields it corresponds to the time of the inelastic electron-phonon interaction.
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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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Huebers H-W, Schubert J, Semenov A, Gol’tsman GN, Voronov BM, Gershenzon EM, et al. NbN phonon-cooled hot-electron bolometer as a mixer for THz heterodyne receivers. In: Chamberlain JM, editor. Proc. SPIE. Vol 3828. Spie; 1999. p. 410–6.
Abstract: We have investigated a phonon-cooled NbN hot electron bolometric (HEB) mixer in the frequency range from 0.7 THz to 5.2 THz. The device was a 3.5 nm thin film with an in- plane dimension of 1.7 X 0.2 micrometers 2 integrated in a complementary logarithmic spiral antenna. The measured DSB receiver noise temperatures are 1500 K, 2200 K, 2600 K, 2900 K, 4000 K, 5600 K and 8800 K. The sensitivity fluctuation, the long term stability, and the antenna pattern were measured and the suitability of the mixer for a practical heterodyne receiver is discussed.
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Boyarskii DA, Gershenzon VE, Gershenzon EM, Gol'tsman GN, Ptitsina NG, Tikhonov VV, et al. On the possibility of determining the microstructural parameters of an oil-bearing layer from radiophysical measurement data. J of Communications Technology and Electronics. 1996;41(5):408–14.
Abstract: A method for the reconstruction of microstructural properties of an oil-bearing rock from the spectral dependence of the transmission factor of submillimeter waves is proposed.
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