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Karasik, B. S., Milostnaya, I. I., Zorin, M. A., Elantev, A. I., Gol'tsman, G. N., & Gershenzon, E. M. (1994). Subnanosecond S-N and N-S switching of YBCO film induced by current pulse. Phys. C: Supercond., 235-240, 1981–1982.
Abstract: A transition of YBCO bridge 60 nm thick from superconducting to normal state induced by an abrupt current step has been studied. A subnanosecond stage has been observed during both S-N and N-S transition. The data obtained can be explained by hot-electron phenomena. On the basis of experimental results a prediction of picosecond switch performance has been made.
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Gol'tsman, G. N., Kouminov, P., Goghidze, I., & Gershenzon, E. M. (1994). Nonequilibrium kinetic inductive response of YBaCuO thin films to low-power laser pulses. Phys. C: Supercond., 235-240, 1979–1980.
Abstract: Transient non-equilibrium kinetic inductive voltage response of YBaCuO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 μm and 1.5 μm wavelength has been revealed. By increasing the sensitivity of 100 ps resolution time registration system and diminishing light intensity (fluence 0.1-1 μJ2/cm2) and transport current (density j≤105 A/cm2) we observed a perculiar bipolar signal form with nearly equal amplitudes of each sign. The integration of the kinetic inductive response over time gives the result which is qualitatively of the same form as the response in the resistive and normal states: nonequilibrium picosecond scale component followed by bolometric nanosecond. Nonequilibrium response is interpreted as suppression of order parameter by excess of quasiparticles followed by a change in resistance in the resistive state and kinetic inductance in superconductive state.
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Gershenzon, E. M., Gol'tsman, G. N., Gogidze, I. G., Semenov, A. D., & Sergeev, A. V. (1991). Processes of electron-phonon interaction in thin YBaCuO films. Phys. C: Supercond., 185-189, 1371–1372.
Abstract: The ultrafast voltage response of YBaCuO films to laser radiation is studied and compared with previously investigated quasiparicles response to radiation of submillimeter wavelength range. Voltage shift under the visible light radiation has two components. Picosecond response realized as suppression superconductivity by nonequilibrium excess quasiparticles, response time is determined by quasiparticles recombination rate. Nanosecond response is probably due to bolometric effect.
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Il’in, K. S., Ptitsina, N. G., Sergeev, A. V., Gol’tsman, G. N., Gershenzon, E. M., Karasik, B. S., et al. (1998). Interrelation of resistivity and inelastic electron-phonon scattering rate in impure NbC films. Phys. Rev. B, 57(24), 15623–15628.
Abstract: A complex study of the electron-phonon interaction in thin NbC films with electron mean free path l=2–13nm gives strong evidence that electron scattering is significantly modified due to the interference between electron-phonon and elastic electron scattering from impurities. The interference T2 term, which is proportional to the residual resistivity, dominates over the Bloch-Grüneisen contribution to resistivity at low temperatures up to 60 K. The electron energy relaxation rate is directly measured via the relaxation of hot electrons heated by modulated electromagnetic radiation. In the temperature range 1.5–10 K the relaxation rate shows a weak dependence on the electron mean free path and strong temperature dependence ∼Tn, with the exponent n=2.5–3. This behavior is explained well by the theory of the electron-phonon-impurity interference taking into account the electron coupling with transverse phonons determined from the resistivity data.
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Ptitsina, N. G., Chulkova, G. M., Il’in, K. S., Sergeev, A. V., Pochinkov, F. S., Gershenzon, E. M., et al. (1997). Electron-phonon interaction in disordered metal films: The resistivity and electron dephasing rate. Phys. Rev. B, 56(16), 10089–10096.
Abstract: The temperature dependence of the resistance of films of Al, Be, and NbC with small values of the electron mean free path l=1.5–10nm has been measured at 4.2–300 K. The resistance of all the films contains a T2 contribution that is proportional to the residual resistance; this contribution has been attributed to the interference between the elastic electron scattering and the electron-phonon scattering. Fitting the data to the theory of the electron-phonon-impurity interference (M. Yu. Reiser and A. V. Sergeev, Zh. Eksp. Teor. Fiz. 92, 224 (1987) [Sov. Phys. JETP 65, 1291 (1987)]), we obtain constants of interaction of the electrons with transverse phonons, and estimate the contribution of this interaction to the electron dephasing rate in thin films of Au, Al, Be, Nb, and NbC. Our estimates are in a good agreement with the experimental data on the inelastic electron-phonon scattering in these films. This indicates that the interaction of electrons with transverse phonons controls the electron-phonon relaxation rate in thin-metal films over a broad temperature range.
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Sergeev, A., Karasik, B. S., Ptitsina, N. G., Chulkova, G. M., Il'in, K. S., & Gershenzon, E. M. (1999). Electron–phonon interaction in disordered conductors. Phys. Rev. B Condens. Matter, 263-264, 190–192.
Abstract: The electron–phonon interaction is strongly modified in conductors with a small value of the electron mean free path (impure metals, thin films). As a result, the temperature dependencies of both the inelastic electron scattering rate and resistivity differ significantly from those for pure bulk materials. Recent complex measurements have shown that modified dependencies are well described at K by the electron interaction with transverse phonons. At helium temperatures, available data are conflicting, and cannot be described by an universal model.
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Verevkin, A. A., Ptitsina, N. G., Chulcova, G. M., Gol'Tsman, G. N., Gershenzon, E. M., & Yngvesson, K. S. (1996). Determination of the limiting mobility of a two-dimensional electron gas in AlxGa1-xAs/GaAs heterostructures and direct measurement of the energy relaxation time. Phys. Rev. B Condens. Matter., 53(12), R7592–R7595.
Abstract: We present results for a method to measure directly the energy relaxation time (τe) for electrons in a single AlxGa1−xAs/GaAs heterojunction; measurements were performed from 1.6 to 15 K under quasiequilibrium conditions. We find τeαT−1 below 4 K, and τe independent of T above 4 K. We have also measured the energy-loss rate, ⟨Q⟩, by the Shubnikov-de Haas technique, and find ⟨Q⟩α(T3e−T3) for T<~4.2 K; Te is the electron temperature. The values and temperature dependence of τe and ⟨Q⟩ for T<4 K agree with calculations based on piezoelectric and deformation potential acoustic phonon scattering. At 4.2 K, we can also estimate the momentum relaxation time, τm, from our measured τe. This leads to a preliminary estimate of the phonon-limited mobility at 4.2 K of μ=3×107 cm2/Vs (ns=4.2×1011 cm−2), which agrees well with published numerical calculations, as well as with an earlier indirect estimate based on measurements on a sample with much higher mobility.
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Sergeev, A. V., Semenov, A. D., Kouminov, P., Trifonov, V., Goghidze, I. G., Karasik, B. S., et al. (1994). Transparency of a YBa2Cu3O7-film/substrate interface for thermal phonons measured by means of voltage response to radiation. Phys. Rev. B Condens. Matter., 49(13), 9091–9096.
Abstract: The transparency of a film/substrate interface for thermal phonons was investigated for YBa2Cu3O7 thin films deposited on MgO, Al2O3, LaAlO3, NdGaO3, and ZrO2 substrates. Both voltage response to pulsed-visible and to continuously modulated far-infrared radiation show two regimes of heat escape from the film to the substrate. That one dominated by the thermal boundary resistance at the film/substrate interface provides an initial exponential decay of the response. The other one prevailing at longer times or smaller modulation frequencies causes much slower decay and is governed by phonon diffusion in the substrate. The transparency of the boundary for phonons incident from the film on the substrate and also from the substrate on the film was determined separately from the characteristic time of the exponential decay and from the time at which one regime was changed to the other. Taking into account the specific heat of optical phonons and the temperature dependence of the group velocity of acoustic phonons, we show that the body of experimental data agrees with acoustic mismatch theory rather than with the model that assumes strong diffusive scattering of phonons at the interface.
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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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Antipov, S. V., Svechnikov, S. I., Smirnov, K. V., Vakhtomin, Y. B., Finkel, M. I., Goltsman, G. N., et al. (2001). Noise temperature of quasioptical NbN hot electron bolometer mixers at 900 GHz. Physics of Vibrations, 9(4), 242–245.
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