Records |
Author |
Gershenzon, E. M.; Gol'tsman, G. N.; Multanovskii, V. V.; Ptitsyna, N. G. |
Title |
Capture of photoexcited carriers by shallow impurity centers in germanium |
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Journal Article |
Year |
1979 |
Publication |
Sov. Phys. JETP |
Abbreviated Journal |
Sov. Phys. JETP |
Volume |
50 |
Issue |
4 |
Pages |
728-734 |
Keywords |
Ge, photoexcited carriers, shallow impurity centers |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Measurements were made of the lifetimes rf of free carriers and the relaxation time 7, of the submillimeter impurity photoconductivity when carriers are captured by attracting shallow donors and acceptom in Ge. It is nod that in samples with capture-center concentration N,Z 10"cm-' the relaxation time 7, greatly exceeds rf in the temperature range 4.2-12 K. The measured values of 7,- are compared with the calculation of cascade recombination by the classical model. To evaluate the data on T,, the distinguishing features of this model are considered for the nonstationary case. The substantial difference betweea the values of rf and T, is attributed to re-emission of the carriers from the excited states of the shallow impurities. |
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1720 |
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Author |
Varyukhin, S. V.; Zakharov, A. A.; Gershenzon, E. M.; Gol'tsman, G. N.; Ptitsina, N. G.; Chulkova, G. M. |
Title |
Low energy excitation in La2CuO4 |
Type |
Journal Article |
Year |
1990 |
Publication |
Sverkhprovodimost': Fizika, Khimiya, Tekhnika |
Abbreviated Journal |
Sverkhprovodimost': Fizika, Khimiya, Tekhnika |
Volume |
3 |
Issue |
5 |
Pages |
832-837 |
Keywords |
metal-dielectric-La2CuO4, monocrystals |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Measurements of transmission and photoconductivity spectra in submillimeter wave length range as well as of capacity C and conductivity G in the region of acoustic frequencies of metal-dielectric-La2CuO4 system at low temperatures are performed using La2CuO4 monocrystals. Optical spectra posses a threshold character, a sharp decrease of transmission and photocoductivity signal occurs in the energy region hν>1.5 MeV. C(ω,T) and G(ω, T) dependences have a universal form typical of Debye type relaxation processes. Relaxation time dependence is of thermoactivated character τ(T)∼exp(ξ/T) with the gap value ξ≅2 meV. It is assumed that excitations with characteristic energy of ∼2 meV exist in La2CuO4. A possible nature of the detected low-energy excitations is discussed. |
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1688 |
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Vakhtomin, Y. B.; Finkel, M. I.; Antipov, S. V.; Smirnov, K. V.; Kaurova, N. S.; Drakinskii, V. N.; Voronov, B. M.; Gol’tsman, G. N. |
Title |
The gain bandwidth of mixers based on the electron heating effect in an ultrathin NbN film on a Si substrate with a buffer MgO layer |
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Journal Article |
Year |
2003 |
Publication |
J. of communications technol. & electronics |
Abbreviated Journal |
J. of communications technol. & electronics |
Volume |
48 |
Issue |
6 |
Pages |
671-675 |
Keywords |
NbN HEB mixers |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Measurements of the intermediate frequency band 900 GHz of mixers based on the electron heating effect (EHE) in 2-nm- and 3.5-nm-thick superconducting NbN films sputtered on MgO and Si substrates with buffer MgO layers are presented. A 2-nm-thick superconducting NbN film with a critical temperature of 9.2 K has been obtained for the first time using a buffer MgO layer. |
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MAIK Nauka/Interperiodica, Birmingham, AL |
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1064-2269 |
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https://elibrary.ru/item.asp?id=17302119 (Полоса преобразования смесителей на эффекте разогрева электронов в ультратонких пленках NbN на подложках из Si с подслоем MgO) |
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Vakhtomin2003 |
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1522 |
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Author |
Zhang, W.; Miao, W.; Li, S. L.; Zhou, K. M.; Shi, S. C.; Gao, J. R.; Goltsman, G. N. |
Title |
Measurement of the spectral response of spiral-antenna coupled superconducting hot electron bolometers |
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Journal Article |
Year |
2013 |
Publication |
IEEE Trans. Appl. Supercond. |
Abbreviated Journal |
IEEE Trans. Appl. Supercond. |
Volume |
23 |
Issue |
3 |
Pages |
2300804-2300804 |
Keywords |
NbN HEB detector |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
Measured spectral response of spiral-antenna coupled superconducting hot electron bolometers (HEBs) often drops dramatically at frequencies that are still within the frequency range of interest (e.g., ~ 5 THz). This is inconsistent with the implied low receiver noise temperatures from the same measurements. To understand this discrepancy, we exhaustively test and calibrate the thermal sources used in Fourier transform spectrometer measurements. We first investigate the absolute emission spectrum of high-pressure Hg arc lamp, then measure the spectral response of two spiral-antenna coupled NbN HEBs with a Martin-Puplett interferometer as spectrometer and 77 K blackbody as broadband signal source. The measured absolute emission spectrum of Hg arc lamp is proportional to frequency, corresponding to an equivalent blackbody temperature of 4000 K at 1 THz, 1500 K at 3 THz, and 800 K at 5 THz, respectively. Measured spectral response of spiral-antenna coupled NbN HEBs, corrected for air absorption, is nearly flat in the frequency range of 0.5-4 THz, consistent with simulated coupling efficiency between HEB and spiral-antenna. These results explain the discrepancy, and prove that spiral-antenna coupled superconducting NbN HEBs work well in a wide frequency range. In addition, this calibration method and these results are broadly applicable to other quasi-optical THz receivers. |
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1051-8223 |
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1371 |
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Author |
Godunova, E. K.; Levin, V. I. |
Title |
Some general features of heat conduction |
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Journal Article |
Year |
1966 |
Publication |
USSR Computational Mathematics and Mathematical Physics |
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USSR Computational Mathematics and Mathematical Physics |
Volume |
6 |
Issue |
6 |
Pages |
212-220 |
Keywords |
mathematics, temperature distribution, rod |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
LET the initial temperature distribution in an infinite insulated rod without a heat source be given by a continuously differentiable function y = f(x), having a single maximum at x = 0 and two points of inflexion. The equation f′ = 0 then has a unique solution x = 0, where f′(x) > 0 for x < 0 and f′(x) < 0 for x > 0, We shall describe this as a one-hymped distribution. We shall assume that f/(x) also satisfies: (1) f(x) > 0 for − ∞ < x < ∞; (2) f(x) and x(fx) are integrable throughout the axis. Then the distribution remains one-humped for all t > 0. |
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0041-5553 |
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Некоторые качественные вопросы теплопроводности; Одногорбое распределение останется одногорбым |
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1701 |
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