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Gershenzon EM, Gol'tsman GN, Kagane ML. Observation of free carrier resonances in p-type germanium at submillimeter wavelengths. Sov Phys Solid State. 1978;20(4):573–9.
Abstract: The spectrum of hole resonances in pure p-Ge for submillimetre in quantizing magnetic fields has been studied and identified. Measurements of photoconductivity spectra of p-Ge were made in the wave range lambda = 2-0.3 mm at temp. of 4.2-15 deg K in magnetic fields H up to 40 Measurements at various frequencies showed that the position of a series of characteristic resonances depends on the frequency of the illumination. This is in line with theoretical conclusions about the effective mass of the carriers increasing with rise in the magnetic field as a result of the interaction of the edge of the valency band with the split spin-orbital interaction of the sub 7 exp + band and the conduction band. The relative intensity of the quantum resonance lines of the free holes depends on the excitation conditions.
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Gershenzon EM, Gol'tsman GN, Kagane ML. Energy spectrum of acceptors in germanium and its response to a magnetic field. Sov Phys JETP. 1977;45(4):769–76.
Abstract: We investigated the spectrum of the submillimeter photoconductivity of p-Ge at helium temperatures and the effects of a magnetic field up to 40 kOe on the spectrum. A large number of lines of transitions between the excited states of the acceptors was observed, some of the lines were identified, and the energies of a number of spectral levels B, Al, Ga, In, and TI in Ge were identified. The results are compared with calculations and with experimental data obtained from the spectra of the photoexcitation of the ground state of the impurities. Using one transition as an example, we discuss the splitting of the excited states of acceptors in the magnetic field and under uniaxial compression.
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Gershenzon EM, Orlov LA, Ptitsina NG. Absorption spectra in electron transitions between excited states of impurities in germanium. JETP Lett. 1975;22(4):95–7.
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Ptitsina NG, Chulkova GM, Gershenzon EM. Influence of the interference of electron-phonon and electron-impurity scattering on the conductivity of unordered Nb films. JETP. 1995;80(5):960–4.
Abstract: The temperature dependence of the resistivity of Nb thin films has been studied at T=4.2-300 K. It has been shown that quantum interference between electron-phonon and electron-impurity scattering determines the temperature dependence of the resistivity of the films investigated over a broad temperature range. The magnitude of the contribution of the electron-phonon-impurity,interference is described satisfactorily by the theory developed by Reizer and Sergeev {Zh. Eksp. Teor. Fiz. 92,2291 (1987) [Sov. Phys. JETP 65, 1291 (1987)l). The interaction constants of electrons with longitudinal and transverse phonons in Nb films have been determined for the first time by comparing the experimental data with the theory. The values of the constants obtained are consistent with the data on the inelastic electron-phonon scattering times in the films investigated. The contribution of the transverse phonons is dominant both in the interference correction to the resistivity and in the electron energy relaxation.
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Verevkin AA, Ptitsina NG, Smirnov KV, Gol’tsman GN, Gershenzon EM, Ingvesson KS. Direct measurements of energy relaxation times on an AlGaAs/GaAs heterointerface in the range 4.2–50 K. JETP Lett. 1996;64(5):404–9.
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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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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Danerud M, Winkler D, Lindgren M, Zorin M, Trifonov V, Karasik B, et al. A fast infrared detector based on patterned YBCO thin film. Supercond Sci Technol. 1994;7(5):321–3.
Abstract: Detectors for infrared radiation ( lambda =0.85 mu m) were made of 50 nm thick YBa2Cu3O7- delta films on LaAlO3 and MgO or 60 nm thick films on NdGaO3. Parallel strips (1 mu m wide by 20 mu m long) were patterned in the films and formed the active device. These devices were designed to detect short infrared laser pulses by electron heating. The detectors were current biased into the resistive and the normal states. The response was studied in direct pulse measurements as well as by amplitude modulation of a laser. The pulse measurements showed a fast picosecond response followed by a slower decay related to phonon escape through the film-substrate interface and heat diffusion in the substrate. The frequency spectra up to 10 GHz showed two slopes with a knee corresponding to the phonon escape time.
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Semenov AD, Goghidze IG, Gol’tsman GN, Sergeev AV, Gershenzon EM. Evidence for the spectral dependence of nonequilibrium picosecond photoresponse of YBaCuO thin films. Appl Phys Lett. 1993;63(5):681–3.
Abstract: The transient voltage photoresponse of current biased YBaCuO thin films to 20 ps laser pulses of 0.63 and 1.54 μm wavelengths is measured for temperatures around the superconducting transition region. The fast picosecond decay of the response is followed by a slow nanosecond relaxation which is associated with the bolometric effect. The magnitude of the fast component of the response varies in proportion to the square root of wavelength that plausibly reflects multiplication processes of photoexcited electrons via electron–electron scattering and interaction with high energy phonons.
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Voronov BM, Gershenzon EM, Gol'tsman GN, Gogidze IG, Gusev YP, Zorin MA, et al. Picosecond range detector base on superconducting niobium nitride film sensitive to radiation in spectral range from millimeter waves up to visible light. Sverkhprovodimost': Fizika, Khimiya, Tekhnika. 1992;5(5):955–60.
Abstract: Fast-operating picosecond detector of electromagnetical radiation is developed on the basis of fine superconducting film of niobium nitride with high sensitivity within spectral range from millimetric waves up to visible light. Detector sensitive element represents structure covering narrow parallel strips with micron sizes included in the rupture of microstrip line. Detecting ability of the detector and time constant measured using amplitude-simulated radiation of reverse wave tubes and pulse radiation of picosecond gas and solid-body lasers, constitute D*≅1010 W-1·cm·Hz-1/2 and τ≤5 ps respectively, at 10 K temperature. The expected value of time constant of the detector at 10 K obtained via extrapolation of directly measured dependence that is, τ ∝ τ-1, constitutes 20 ps. Experimental data demonstrate that detection mechanism is linked with electron heating effect.
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Varyukhin SV, Zakharov AA, Gershenzon EM, Gol'tsman GN, Ptitsina NG, Chulkova GM. Low energy excitation in La2CuO4. Sverkhprovodimost': Fizika, Khimiya, Tekhnika. 1990;3(5):832–7.
Abstract: 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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