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Author Cherednichenko, S.; Kroug, M.; Merkel, H.; Kollberg, E.; Loudkov, D.; Smirnov, K.; Voronov, B.; Gol'tsman, G.; Gershenzon, E.
Title Local oscillator power requirement and saturation effects in NbN HEB mixers Type Conference Article
Year 2001 Publication Proc. 12th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 12th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 273-285
Keywords NbN HEB mixers, LO power, local oscillator power, saturation effect, dynamic range
Abstract (down) The local oscillator power required for NbN hot-electron bolometric mixers (P LO ) was investigated with respect to mixer size, critical temperature and ambient temperature. P LO can be decreased by a factor of 10 as the mixer size decreases from 4×0.4 µm 2 to 0.6×0.13 µm 2 . For the smallest volume mixer the optimal local oscillator power was found to be 15 nW. We found that for such mixer no signal compression was observed up to an input signal of 2 nW which corresponds to an equivalent input load of 20,000 K. For a constant mixer volume, reduction of T c can decrease optimal local oscillator power at least by a factor of 2 without a deterioration of the receiver noise temperature. Bath temperature was found to have minor effect on the receiver characteristics.
Address
Corporate Author Thesis
Publisher Place of Publication San Diego, CA, USA Editor Jet Propulsion Laboratory, California Inst.it.u.t.e of Technology
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 318
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Author Varyukhin, S. V.; Zakharov, A. A.; Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsyna, N. G.; Chulkova, G. M.
Title AC losses and submillimeter absorption in single crystals La2CuO4 Type Journal Article
Year 1990 Publication Phys. B Condens. Mat. Abbreviated Journal Phys. B Condens. Mat.
Volume 165-166 Issue Pages 1269-1270
Keywords metal-dielectric-La2Cu04
Abstract (down) The La2CuO4 single crystals were used to carry out the measurements of transmission spectra within the submillimeter range of wavelengths, as well as the capacitance C and conductivity G in the region of acoustic frequencies of the metal-dielectric-La2Cu04 system at low temperatures. The optical spectra display a threshold character. There takes place a sharp decreasing of transmission signal in the energy range of hυ>1.5meV. The C(ω,T) and G(ω,T) dependences have a universal form characteristic of relaxation processes of the Debye type. The relaxation time dependence displays a thermoactivation character τ(T)-exp(ξ/T) with a gap value of ξ≃2meV,coinciding with the optical one. It is assumed that there exist excitations with a characteristic energy ~ 2meV in La2Cu04.A possible nature of the revealed low-energy excitations is discussed.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4526 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1686
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Author Gershenzon, E. M.; Gol'tsman, G. N.; Multanovskii, V. V.; Ptitsina, N. G.
Title Kinetics of electron and hole binding into excitons in germanium Type Journal Article
Year 1983 Publication Sov. Phys. JETP Abbreviated Journal Sov. Phys. JETP
Volume 57 Issue 2 Pages 369-376
Keywords Ge, electron and hole binding
Abstract (down) The kinetics of binding of free carriers'into excitons under stationary and nonstationary conditions is studied by investigating the submillimeter photoconductivity of Ge in a wide range of temperatures and of excitation levels. It is shown that the absolute values and the temperature dependence of the binding cross section (o- T-'.' ) can be satisfactorily described by the cascade recombination theory. The value of o and its temperature dependence differ significantly from the cross sections, measured in the same manner, for capture by attracting small impurities. Under nonstationary conditions, just as in the case of recombination with shallow impurities, a signifi- cant role is played by the sticking of the carriers in highly excited states.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1711
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Author Mel’nikov, A. P.; Gurvich, Y. A.; Shestakov, L. N.; Gershenzon, E. M.
Title Magnetic field effects on the nonohmic impurity conduction of uncompensated crystalline silicon Type Journal Article
Year 2001 Publication Jetp Lett. Abbreviated Journal Jetp Lett.
Volume 73 Issue 1 Pages 44-47
Keywords uncompensated crystalline silicon, nonohmic impurity conduction, magnetic field
Abstract (down) The impurity conduction of a series of crystalline silicon samples with the concentration of major impurity N ≈ 3 × 1016 cm−3 and with a varied, but very small, compensation K was measured as a function of the electric field E in various magnetic fields H-σ(H, E). It was found that, at K < 10−3 and in moderate E, where these samples are characterized by a negative nonohmicity (dσ(0, E)/dE < 0), the ratio σ(H, E)/σ(0, E) > 1 (negative magnetoresistance). With increasing E, these inequalities are simultaneously reversed (positive nonohmicity and positive magnetoresistance). It is suggested that both negative and positive nonohmicities are due to electron transitions in electric fields from impurity ground states to states in the Mott-Hubbard gap.
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Corporate Author Thesis
Publisher Place of Publication Editor
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 Approved no
Call Number Serial 1752
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Author Aksaev, E. E.; Gershenzon, E.M.; Gol'tsman, G. N.; Mirskij, G. I.; Semenov, A. D.
Title Submillimetric spectrometer-relaxometer based on backward-wave tubes with picosecond time resolution Type Journal Article
Year 1991 Publication Pribory i Tekhnika Eksperimenta Abbreviated Journal Pribory i Tekhnika Eksperimenta
Volume 34 Issue 2 Pages 125-131
Keywords BWO, applications
Abstract (down) The high-sensitive automatic spectrometer-relaxometer based on backward-wave tubes in the range of 4÷0.25 mm was described permitting to study the response kinetics of sample under investigation in any point of this range with the resolution time of 10-11 s. The relaxation measurements were conducted using oscillation beats of two adequate tubes, the frequency of one of them was fixed, while that of the other one was changeable. The amplitude-frequency characteristic of the response under the conditions of synchronous reception was recorded at beat frequency variation from 107 to 1010 Hz. The high sensitivity was reached by decreasing the device recording band down to 100 Hz in the whole measuring range.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language 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 Approved no
Call Number Serial 1683
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