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Author Gershenzon, E. M.; Gol'tsman, G. N.; Mirskii, G. I.
Title Submillimeter backward-wave-tube spectrometer-relaxometer Type Journal Article
Year 1987 Publication Pribory i Tekhnika Eksperimenta Abbreviated Journal Pribory i Tekhnika Eksperimenta
Volume 30 Issue 4 Pages 131-137
Keywords (down) BWO, applications
Abstract A backward-wave-tube (BWT) spectrometer-relaxometer is described that is designed for study of the relaxation characteristics of photoconductors in the wavelength range of 2-0.25 mm – in particular, to measure the relaxation times of the submillimeter photoconductivity of germanium in the range of 10[sup:-4]-10[sup:-9] sec and to determine from these data the concentration of compensating impurities of from 10[sup:10] to 10[sup:14] cm[sup:-3]. The instrument uses the beats of the oscillations of two BWTs and records the amplitude-frequency response of the specimen with variation of the beat frequency from 10[sup:4] to 10[sup:8] Hz with accumulation of the desired signal for less than or equal to1 sec by means of a quadrature synchronous detector. The beat frequency is stabilized and the quadrature voltages of the synchronous detector are formed by means of phase-locked loops.
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Language Russian Summary Language Original Title
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Notes Approved no
Call Number Serial 1699
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Author Gershenzon, E. M.; Gol'tsman, G. N.; Semenov, A. D.
Title Submillimeter backward wave tube spectrometer for measuring superconducting film transmission Type Journal Article
Year 1983 Publication Pribory i Tekhnika Eksperimenta Abbreviated Journal Pribory i Tekhnika Eksperimenta
Volume 26 Issue 5 Pages 134-137
Keywords (down) BWO spectroscopy, spectrometer, transmission
Abstract A spectrometer employing six backward wave tubes is described. It is intended for investigation of superconductors in the 0.2-3 mm range of wave lengths. During the measurement of the transmission spectrum it is possible to determine the energy gap for superconduct1ng films 50 to 4000 A thick. The transmission factor can vary from 10-1 to 10-9. Spectrum of relation of film transmission factors in superconducting and normal states is measured for determining the energy gap 2 Δ. The transmission spectrum obtained by means of a computer for vanadium film 300 A thick is given as an example. The energy gap 2 Δ = 1.4 MeV
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Russian Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0032-8162 ISBN Medium
Area Expedition Conference
Notes Субмиллиметровый спектрометр с лампами обратной волны для измерения пропускания сверхпроводниковых пленок Approved no
Call Number Serial 1713
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Author Chulcova, G. M.; Ptitsina, N. G.; Gershenzon, E. M.; Gershenzon, M. E.; Sergeev, A. V.
Title Effect of the interference between electron-phonon and electron-impurity (boundary) scattering on resistivity Nb, Al, Be films Type Conference Article
Year 1996 Publication Czech J. Phys. Abbreviated Journal Czech J. Phys.
Volume 46 Issue S5 Pages 2489-2490
Keywords (down) Al, Be, Nb films
Abstract The temperature dependence of the resistivity of thin Nb, Al, Be films has been studied over a wide temperature range 4-300 K. We have found that the temperature-dependent correction to the residual resistivity is well described by the sum of the Bloch-Grüneisen term and the term originating from the interference between electron-phonon and electron-impurity scattering. Study of the transport interference phenomena allows to determine electron-phonon coupling in disordered metals. The interference term is proportional to T2 and also to the residual resistivity and dominates over the Bloch-Grüneisen term at low temperatures (T<40 K).
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0011-4626 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1767
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Author Smirnov, K. V.; Ptitsina, N. G.; Vakhtomin, Y. B.; Verevkin, A. A.; Gol’tsman, G. N.; Gershenzon, E. M.
Title Energy relaxation of two-dimensional electrons in the quantum Hall effect regime Type Journal Article
Year 2000 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 71 Issue 1 Pages 31-34
Keywords (down) 2DEG, GaAs/AlGaAs heterostructures
Abstract The mm-wave spectroscopy with high temporal resolution is used to measure the energy relaxation times τe of 2D electrons in GaAs/AlGaAs heterostructures in magnetic fields B=0–4 T under quasi-equilibrium conditions at T=4.2 K. With increasing B, a considerable increase in τe from 0.9 to 25 ns is observed. For high B and low values of the filling factor ν, the energy relaxation rate τ −1e oscillates. The depth of these oscillations and the positions of maxima depend on the filling factor ν. For ν>5, the relaxation rate τ −1e is maximum when the Fermi level lies in the region of the localized states between the Landau levels. For lower values of ν, the relaxation rate is maximum at half-integer values of τ −1e when the Fermi level is coincident with the Landau level. The characteristic features of the dependence τ −1e (B) are explained by different contributions of the intralevel and interlevel electron-phonon transitions to the process of the energy relaxation of 2D electrons.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-3640 ISBN Medium
Area Expedition Conference
Notes http://jetpletters.ru/ps/899/article_13838.shtml (“Энергетическая релаксация двумерных электронов в области квантового эффекта Холла”) Approved no
Call Number Serial 1559
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Author Verevkin, A. A.; Ptitsina, N. G.; Smirnov, K. V.; Gol’tsman, G. N.; Gershenzon, E. M.; Ingvesson, K. S.
Title Direct measurements of energy relaxation times on an AlGaAs/GaAs heterointerface in the range 4.2–50 K Type Journal Article
Year 1996 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 64 Issue 5 Pages 404-409
Keywords (down) 2DEG, AlGaAs/GaAs heterostructures
Abstract The temperature dependence of the energy relaxation time τe (T) of a two-dimensional electron gas at an AlGaAs/GaAs heterointerface is measured under quasiequilibrium conditions in the region of the transition from scattering by acoustic phonons to scattering with the participation of optical phonons. The temperature interval of constant τe, where scattering by the deformation potential predominates, is determined. In the preceding, low-temperature region, where piezoacoustic and deformation-potential-induced scattering processes coexist, τ e decreases slowly with increasing temperature. Optical phonons start to participate in the scattering processes at T∼25 K (the characteristic phonon lifetime was equal to τLOτ4.5 ps). The energy losses calculated from the τe data in a model with an effective nonequilibrium electron temperature agree with the published data obtained under strong heating conditions.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-3640 ISBN Medium
Area Expedition Conference
Notes http://jetpletters.ru/ps/981/article_14955.shtml (“Прямые измерения времен энергетической релаксации на гетерогранице AlGaAs/GaAs в диапазоне 4.2 – 50 К”) Approved no
Call Number Serial 1608
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