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    Wyświetlanie 1-42 z 42
    Tytuł:
    A New Look on the Skin Depth of the Normal Skin Effect in a Metal Submitted to a Frequency-Dependent Electromagnetic Field
    Autorzy:
    Olszewski, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1400153.pdf
    Data publikacji:
    2013-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30+q
    Opis:
    The theory of the skin depth in metals is re-examined by revision of the conductivity expression entering the Maxwell equations leading to the normal skin effect. In fact this conductivity formula should be improved by considering its special behaviour at low temperatures in case of the presence of the magnetic field. For very pure specimens and very low temperatures the correction of the conductivity tensor leads to the skin depth approximately proportional to the square root of the amplitude strength of the magnetic field.
    Źródło:
    Acta Physica Polonica A; 2013, 123, 4; 750-751
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Small and Large Signal Analysis of Terahertz Generation from InN n$\text{}^{+}$nn$\text{}^{+}$ Structures with Free-Carrier Grating
    Autorzy:
    Gružinskis, V.
    Shiktorov, P.
    Starikov, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041674.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    Opis:
    Electron transport in long (up to 15μm) InN n$\text{}^{+}$nn$\text{}^{+}$ structures is theoretically investigated by the Monte Carlo particle technique at low lattice temperatures when optical phonon emission is the dominating scattering mechanism. It is shown that at constant bias a free-carrier grating can be formed inside the n-region. Such a grating is found to be responsible for microwave power generation in the THz frequency range. The generation mechanism is similar to that in submicron n$\text{}^{+}$nn$\text{}^{+}$ structures under quasiballistic transport conditions.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 163-168
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Small-Signal Characterization of FET/HEMT for Terahertz Applications
    Autorzy:
    Starikov, E.
    Shiktorov, P.
    Gružinskis, V.
    Marinchio, H.
    Nouvel, P.
    Torres, J.
    Palermo, C.
    Chusseau, L.
    Varani, L.
    Ziadé, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505675.pdf
    Data publikacji:
    2011-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    Opis:
    Calculations of the small-signal response of InGaAs HEMTs by using the hydrodynamic approach coupled with a pseudo-2D Poisson equation are performed. The spectra of small-signal admittance and impedance are found to demonstrate series of the resonant peaks corresponding to excitation of plasma waves. Possibilities and conditions of instability onset and THz signal detection are discussed.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 2; 203-205
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modeling of THz-Electro-Optical Sampling Measurements
    Autorzy:
    Shiktorov, P.
    Starikov, E.
    Gružinskis, V.
    Varani, L.
    Reggiani, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813215.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    Opis:
    We carry out a theoretical analysis of THz-electro-optical sampling experimental technique applied to semiconductor structures. The difficulties/impossibility of determining the small-signal conductivity spectrum in the framework of such a technique are analyzed and discussed.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 913-916
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Monte Carlo Simulation of Noise and THz Generation in InP FET at Excess of Electrons in Channel
    Autorzy:
    Gružinskis, V.
    Shiktorov, P.
    Starikov, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505736.pdf
    Data publikacji:
    2011-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    Opis:
    Electron transport and drain current noise in field effect transistor with $n^+$ $nn^+$ InP channel have been studied by Monte Carlo particle simulation which simultaneously solves the Boltzmann transport and pseudo-2D Poisson equations. It is shown that at gate voltages giving excess electron concentration in n-region of channel the drain current self-oscillations in THz frequency range are possible. The self-oscillations are driven by electron plasma instability.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 2; 215-217
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Asymmetrically Shaped Pseudomorphic Modulation Doped Structure for Microwave Detection
    Autorzy:
    Kozič, A.
    Paškevič, Č.
    Sužiedėlis, A.
    Gradauskas, J.
    Ašmontas, S.
    Szerling, A.
    Wrzesińska, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/2047175.pdf
    Data publikacji:
    2006-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    85.30.De
    72.30.+q
    Opis:
    In this paper we propose a microwave detector based on a AlGaAs/InGaAs/GaAs structure. Its operation relies on non-uniform carrier heating of the two-dimensional electron gas in the microwave electric fields which is a result of the asymmetric shape of the device fabricated on the base of pseudomorphic modulation doped AlGaAs/InGaAs/GaAs structure. The voltage sensitivity of the device at nitrogen temperature is 38 V/W for 10 GHz radiations and is higher compared to that of modulation doped AlGaAs/GaAs of the same configuration.
    Źródło:
    Acta Physica Polonica A; 2006, 110, 6; 845-849
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetoconductivity of GaAs Transistors as Detectors of THz Radiation
    Autorzy:
    Łusakowski, J.
    Knap, W.
    Kamińska, E.
    Piotrowska, A.
    Gavrilenko, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/2035755.pdf
    Data publikacji:
    2003-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    73.61.Ey
    Opis:
    Magnetotransport characterisation of field effect transistors processed on GaAs/GaAlAs heterostructure was done at 4.2 K for magnetic fields (B) up to 7 T. Three field effect transistors were processed on a single dice and differed by the length (L) of the gate. Electron mobility (μ) in field effect transistors was estimated from dependence of transistor's conductivity vs. B. The results show a decrease inμ with decreasing L that suggests that scattering by edges of the gated part of a transistor limits the electron mobility. Quality factor (Q) of transistors as resonant detectors of THz radiation was calculated. A high value of Q shows that such field effect transistors with sub-micron L are promising devices that can operate at THz frequencies.
    Źródło:
    Acta Physica Polonica A; 2003, 103, 6; 545-551
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Resistive Sensor for Short High-Power Microwave Pulse Measurement in Millimeter Wave Range
    Autorzy:
    Tamošiūnas, V.
    Kancleris, Ž
    Dagys, M.
    Simniškis, R.
    Agee, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/1177568.pdf
    Data publikacji:
    2005-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    85.30.De
    Opis:
    We report on the numerical investigation of the resistive sensor for the 78-118 GHz range. A three-dimensional finite-difference time-domain method was applied to simulate the wave propagation within a waveguide segment with the semiconductor sensor attached to a wider wall of the wave-guide. The electric field distribution, voltage standing-wave ratio and the average electric field dependences on frequency have been determined for several sets of dimensions and specific resistances of the sample. It is demonstrated that a proper selection of the dimensions and specific resistance of the sample can compensate the waveguide dispersion and the decrease of the electron heating effect with frequency. Therefore, a nearly constant sensitivity of the sensor can be obtained for the entire frequency range.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 2; 420-424
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Plasma Oscillations in Nanotransistors: Application to THz Radiations Detection and Generation
    Autorzy:
    Marinchio, H.
    Sabatini, G.
    Palermo, C.
    Nouvel, P.
    Torres, J.
    Varani, L.
    Shiktorov, P.
    Starikov, E.
    Gružinskis, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505457.pdf
    Data publikacji:
    2011-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.15.Nj
    72.20.Ht
    72.30.+q
    Opis:
    By means of a numerical hydrodynamic model, we consider the mechanism of collective plasma oscillations in a field-effect transistor channel under different excitations and biasing conditions. First, we consider the case of a device externally-excited by a harmonic optical beating or an electronic excitation under constant current condition at the drain. Both situations exhibit sharp resonances related to the first odd plasma modes illustrating the possibility of using the HEMT as a terahertz photomixer or detector. Then, we demonstrate that the frequencies, amplitudes and quality factors of the resonances can be strongly modified by varying the drain biasing condition from current- to voltage-driven operation.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 2; 103-106
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    High-Frequency Noise in Modern FET/HEMT Channels Caused by the Excitation of 2D-Plasma Waves
    Autorzy:
    Shiktorov, P.
    Starikov, E.
    Gružinskis, V.
    Varani, L.
    Reggiani, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505464.pdf
    Data publikacji:
    2011-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    72.70.+m
    Opis:
    The problems related with the intrinsic noise in FET/HEMT channels induced by continuous branching of the total current between channel and gate are considered in the framework of a simple analytical model and its predictions on the current-noise spectra. Main branching-induced effects such as the appearance of an additional noise related to the excitation of plasma waves, its dependence on FET/HEMT embedding circuits, interference properties, etc. are analysed.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 2; 117-120
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    THz Emission Induced by an Optical Beating in Nanometer-Length High-Electron-Mobility Transistors
    Autorzy:
    Nouvel, P.
    Torres, J.
    Marinchio, H.
    Laurent, T.
    Palermo, C.
    Varani, L.
    Teppe, F.
    Shiktorov, P.
    Starikov, E.
    Gruzinskis, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505652.pdf
    Data publikacji:
    2011-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.15.Nj
    72.20.Ht
    72.30.+q
    Opis:
    Experimental results of direct measurement of resonant terahertz emission optically excited in InGaAs HEMT channels are presented. The emission was attributed to two-dimensional plasma waves excited by photogeneration of electron-hole pairs in the HEMT channel at the frequency of the beating of two cw-laser sources. The presence of resonances for the radiation emission in the range of $f_0$ ± 10 GHz (with $f_0$ from 0.3 up to 0.5 THz) detected by a Si-bolometer is found. The intensity of THz emission exhibits a nonlinear growth with increase of the pumping power.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 2; 199-202
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Theoretical Investigation of Large-Signal Noise in Nanometric Schottky-Barrier Diodes Operating in External Resonant Circuits
    Autorzy:
    Shiktorov, P.
    Starikov, E.
    Gružinskis, V.
    Varani, L.
    Vaissière, J.
    Reggiani, L.
    Pérez, S.
    González, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/1178800.pdf
    Data publikacji:
    2005-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    72.70.+m
    Opis:
    We report Monte Carlo simulations of electronic noise in heavily doped nanometric GaAs Schottky-barrier diodes operating in series with a parallel resonant circuit when a high-frequency large-signal voltage is applied to the whole system. Significant modifications of the noise spectrum with respect to the unloaded diode are found to occur in the THz-region.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 2; 396-399
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of Conditions for Free-Carrier Grating Formation in InP n⁺nn⁺ Structures using Monte Carlo Technique
    Autorzy:
    Gružinskis, V.
    Shiktorov, P.
    Starikov, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813353.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    72.70.+m
    Opis:
    Electron transport in 5μm long InP n⁺nn⁺ structure with the n-region doping of $10^{15} cm^{-3}$ is theoretically investigated by the Monte Carlo particle technique at low lattice temperature (T = 10 K), when dominating scattering mechanism is the optical phonon emission. It is shown that at the constant bias a free-carrier grating can be formed inside the n-region. The free-carrier grating formation conditions are analysed by Monte Carlo particle simulation of electric field profiles and noise in the considered InP structure.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 943-946
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Plasma Instability Noise in InP n⁺nn⁺ Structures: Monte Carlo Simulation
    Autorzy:
    Gružinskis, V.
    Shiktorov, P.
    Starikov, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813377.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    72.70.+m
    Opis:
    The current noise in n⁺nn⁺ InP structures at dominating low temperature (T = 10 K) optical phonon emission is simulated by Monte Carlo particle technique. The n-region length of simulated structures is varied from 1 to 100 μm. The peaks related to the near collisionless and optical phonon emission dominated plasma instabilities are recognized in current noise spectral density spectra.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 947-950
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Monte Carlo Calculation of High Frequency Mobility and Diffusion Noise in Nitride-Based Semiconductors
    Autorzy:
    Starikov, E.
    Shiktorov, P.
    Gružinskis, V.
    Varani, L.
    Vaissière, J. C.
    Palermo, C.
    Reggiani, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041806.pdf
    Data publikacji:
    2005-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    72.70.+m
    Opis:
    Monte Carlo simulations of high-field transport in semiconductor nitrides, GaN and InN, is used to calculate the velocity-field characteristics and the high-frequency behavior of the differential mobility, spectral density of velocity fluctuations, and noise temperature. It is found that due to very short relaxation time scales of nitrides, the characteristic frequencies associated with extrema and cutoff decay of the negative differential mobility, etc. are shifted to higher frequency range with respect to the case of standard A$\text{}_{3}$B$\text{}_{5}$ compounds. This property is favorable for applications of nitrides in the THz frequency range.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 2; 408-411
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Phonon-plasmon interactions in inhomogeneous semiconductor plasma embedded with nanoparticle cluster
    Autorzy:
    Ghosh, S.
    Dubey, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1050820.pdf
    Data publikacji:
    2018-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    72.50.+b
    73.22.Lp
    Opis:
    Phonon-plasmon interaction in inhomogeneous piezosemiconductor embedded with a nanoparticle cluster is examined using hydrodynamic model of plasma and macroscopic model of piezoelectric media. Present work dealt with the extensive investigation of acoustic wave amplification characteristics. The effects of density gradient δ and non-dimensional parameter l related to nanoparticle cluster on acoustic gain have been studied with varying medium electron density n_{0e}, wave frequency ω and velocity ratio ϑ_{0}/ϑ_{s}. The results so obtained, infer that the varying inhomogeneity and presence of nanoparticle cluster within the semiconductor plasma medium play decisive role in depicting the gain characteristics of acoustic wave.
    Źródło:
    Acta Physica Polonica A; 2018, 133, 5; 1287-1293
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Density Gradient on the Acousto-Electric Wave Instability in Ion-Implanted Semiconductor Plasmas
    Autorzy:
    Ghosh, S.
    Khare, Pragati
    Powiązania:
    https://bibliotekanauki.pl/articles/2044639.pdf
    Data publikacji:
    2006-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.72.Vv
    72.30.+q
    82.70.Dd
    Opis:
    Using hydrodynamic model of inhomogeneous plasma, an analytical investigation of excitation of acousto-electric mode was made in n-type piezoelectric ion-implanted semiconductor plasma. By employing the multi-fluid balance equations along with the elastic and Maxwell equations, a compact dispersion relation for the cases in which colloidal grains are either stationary (ϑ$\text{}_{0d}$=0) or streaming (ϑ$\text{}_{0d}$≢0$) is derived. We find that the choice of homogeneous medium is favorable in achieving higher acoustic gain per radian and the results of the investigation should be useful in understanding the characteristics of longitudinal acousto-electric wave in ion-implanted piezoelectric semiconductor whose main constituents are electrons and negatively charged colloidal particles.
    Źródło:
    Acta Physica Polonica A; 2006, 109, 2; 187-197
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Coherent Terahertz Radiation Generation Assisted by Low-Temperature Optical Phonon Emission: Achievements and Perspectives
    Autorzy:
    Shiktorov, P.
    Starikov, E.
    Gružinskis, V.
    Varani, L.
    Reggiani, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813188.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Ht
    72.30.+q
    73.63.Hs
    Opis:
    The conditions for THz radiation generation caused by electron transite time resonance in momentum and real spaces under low-temperature optical-phonon emission are analyzed. It is shown that such a phenomenon provides a unique possibility to realize the sub-THz and THz radiation generation at the border of the electrooptical and electronic techniques by using both the approaches: (i) amplification of transverse electromagnetic waves in 3D bulk materials and 2D quantum wells, and (ii) longitudinal current instabilities in submicron and overmicron n⁺nn⁺ diodes.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 795-802
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Frequency Influence on the Hot-Electron Noise Reduction in GaAs Operating under Periodic Signals
    Autorzy:
    Persano Adorno, D.
    Capizzo, M.
    Pizzolato, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813386.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.70.+m
    05.40.Ca
    72.30.+q
    Opis:
    A Monte Carlo study of the role of the frequency on the hot-electron intrinsic noise reduction in an n-type GaAs bulk driven by two mixed cyclostationary electric fields is presented. Previous numerical results showed the possibility to reduce the diffusion noise under specific wave-mixing conditions. In this work the variations of the noise properties are investigated by computing and integrating the spectral density of the velocity fluctuations. We found that the effect of reduction of the noise level due to the addition of a second field at twice frequency is almost independent of the frequency.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 979-983
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Vertical Electron Transport in GaN/AlGaN Heterostructures
    Autorzy:
    Reklaitis, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1178371.pdf
    Data publikacji:
    2005-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.40.Kp
    72.20.-i
    72.30.+q
    Opis:
    Nonequilibrium dc and large-signal ac vertical electron transport in GaN/AlGaN heterostructures is investigated by Monte Carlo simulations. The symmetric two-barrier GaN/AlGaN heterostructures are studied. The results of simulations show that polarization charges have a profound effect on dc and large-signal ac characteristics of vertical electron transport in GaN/AlGaN heterostructures. Under certain composition, geometry and doping profile, the GaN/AlGaN heterostructures may become bipolar, i.e., the inversion layers may originate at heterointerfaces due to strong built-in electric fields, which are induced by polarization charges.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 2; 261-266
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Generation of Terahertz Radiation by Large-Aperture Photoconductive Antennas in Condition of a High Level Excitation
    Autorzy:
    Trukhin, V.
    Buyskikh, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1505694.pdf
    Data publikacji:
    2011-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    41.60.-m
    72.20.Jv
    Opis:
    Theoretical and experimental results about generation coherent terahertz (THz) radiation in photoconductive medium in condition of a high level excitation are presented. Employing self-consistent analytical approach to the set of non-equilibrium Boltzmann equation for charge carriers and Maxwell equations for electromagnetic radiation we have studied the radiation phenomena in non-equilibrium e-h plasma excited in the photoconductive gap of terahertz radiating large-aperture photoconductive antenna by an ultrashort laser pulse. Equally with the effect of the radiation screening, the effect of the non-linear absorption of an optical pump pulse (bleaching of photoconductive medium) was taken into account. It was shown that the effect of nonlinear absorption reconstructs the dynamics of the generation of terahertz radiation and must take into account the effects associated with the spread of the generated wave and the wave of excitation.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 2; 206-209
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Numerical Solution of the Imaginary-Axis Eliashberg Equations
    Autorzy:
    Szczęśniak, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2044638.pdf
    Data publikacji:
    2006-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.72.Vv
    72.30.+q
    82.70.Dd
    Opis:
    In the paper, we solve the imaginary-axis Eliashberg equations. We calculate numerically self-consistently the superconducting order function, the wave function renormalization factor, and the energy shift function as a function of the Matsubara frequency. We consider different values of the average number of the electrons per lattice site. Additionally, we study the temperature dependence of the order function and the wave function renormalization factor. The possible extension of the Eliashberg theory to the case of the high-T$\text{}_{C}$ superconductors was also briefly discussed.
    Źródło:
    Acta Physica Polonica A; 2006, 109, 2; 179-186
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Plasma Edge Modification in Strongly Compensated Semiconductors
    Autorzy:
    Szuszkiewicz, W.
    Dybko, K.
    Bardyszewski, W.
    Julien, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/1943840.pdf
    Data publikacji:
    1995-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    71.45.Gm
    78.30.Fs
    Opis:
    We demonstrate that the electron-impurity interaction can modify the reflectivity in the vicinity of plasma minimum giving rise to a small dip on the plasma edge. Experimental spectra taken for Hg$\text{}_{1-x}$Co$\text{}_{x}$Se for x < 0.02 at various temperatures confirm this theoretical prediction. The position of the structure can be used to determine the plasma frequency in highly compensated materials at low temperatures.
    Źródło:
    Acta Physica Polonica A; 1995, 88, 5; 1048-1052
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Plasmon-Phonon Coupling on the Electron-Impurity Interaction in the Free-Carrier Absorption
    Autorzy:
    Szuszkiewicz, W.
    Bardyszewski, W.
    Julien, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/1877134.pdf
    Data publikacji:
    1995-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.45.Gm
    78.30.Fs
    72.30.+q
    Opis:
    An experimental and theoretical evidence that the electron-impurity scattering is modified in the presence of the electromagnetic field oscillating with the frequency corresponding to the optical phonon energy is given. The coupled plasmon-phonon mode related feature in the reflectivity spectrum can be used to determine the upper edge of the LO phonon frequency band in highly doped materials.
    Źródło:
    Acta Physica Polonica A; 1995, 87, 2; 555-558
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Finite-Difference Time-Domain Simulation of Mid- and Far-Infrared Quantum Cascade Lasers
    Autorzy:
    Tamošiūnas, V.
    Kancleris, Ž.
    Dagys, M.
    Simniškis, R.
    Tamošsiūnienė, M.
    Valušis, G.
    Strasser, G.
    Unterrainer, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041682.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    78.66.-w
    85.30.De
    Opis:
    We present simulations of mid- and far-infrared quantum cascade lasers operating with/without external magnetic field. Maxwell-Bloch solver based on the finite-difference time-domain method was used in our investigation. Reduction of the far-infrared quantum cascade laser emission intensity is associated with increased optical losses in highly doped layers when magnetic field is changed from 4.2 T to 6.2 T. A simulated emission spectrum of mid-infrared disc-shaped quantum cascade laser with 60μm radius is consistent with the experimentally observed irregular spacing between quantum cascade laser emission lines.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 179-183
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Broad Band THz Sensing by 2DEG Bow-Tie-Type Diodes
    Autorzy:
    Valušis, G.
    Seliuta, D.
    Tamošiūnas, V.
    Širmulis, E.
    Balakauskas, S.
    Gradauskas, J.
    Sužiedėlis, A.
    Ašmontas, S.
    Anbinderis, T.
    Narkūnas, A.
    Papsujeva, I.
    Lisauskas, A.
    Roskos, H. G.
    Köhler, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041684.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.50.-h
    85.30.De
    72.30.+q
    Opis:
    We suggest a novel approach to detect broad band, 0.078-2.52 THz, electromagnetic radiation at room temperature using an asymmetrically-shaped bow-tie diode based on a modulation-doped GaAs/AlGaAs structure. We show that the voltage sensitivity in the range from 0.078 THz up to 0.8 THz has a plateau and its value is within 0.3-0.5 V/W. We consider the bow-tie diode design to increase the sensitivity of the device.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 184-187
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Studies of Response of Metal - Porous Silicon Structures to Microwave Radiation
    Autorzy:
    Stupakova, J.
    Ašmontas, S.
    Gradauskas, J.
    Zagadskij, V.
    Shatkovskis, E.
    Sužiedėlis, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2047172.pdf
    Data publikacji:
    2006-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    78.55.Mb
    85.30.De
    Opis:
    Structures containing layers of porous silicon with two metal contacts are investigated. Porous silicon is manufactured by anodizing p-type crystalline silicon plates of resistivity of 0.4 Ω cm. Contacts for the samples are made by additional boron doping of the surface and by thermal evaporation of aluminium. Resistance and current-voltage characteristics are investigated. Response of the porous silicon layer containing structures under action of pulsed microwave radiation was investigated for the first time. The origin of the response is discussed.
    Źródło:
    Acta Physica Polonica A; 2006, 110, 6; 817-822
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Impurity Charge Correlation on Free-Carrier Absorption
    Autorzy:
    Szuszkiewicz, W.
    Sobkowicz, P.
    Witkowska, B.
    Bardyszewski, W.
    Julien, C.
    Balkanski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1929654.pdf
    Data publikacji:
    1993-09
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.45.Gm
    72.30.+q
    75.50.Pp
    Opis:
    Impurity-mediated free-carrier absorption was analyzed theoretically taking into account the possible spatial impurity correlations. The effect of correlations was included via the structure factor S(q) obtained from finite temperature Monte Carlo simulations of ordering in the impurity system. From the comparison of the experimental data with the results of calculations it is demonstrated that the ordering of charged centers exists for HgSe:Fe in a wide temperature range.
    Źródło:
    Acta Physica Polonica A; 1993, 84, 3; 559-562
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Charge Carrier Heating Effect in Porous Silicon Structures Investigated by Microwaves
    Autorzy:
    Gradauskas, J.
    Šatkovskis, E.
    Česnys, A.
    Stupakova, J.
    Sužiedėlis, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813389.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    61.43.Gt
    78.70.Gq
    72.30.+q
    Opis:
    Diode-like samples, containing porous silicon structures, were investigated by microwave radiation pulses. The resistance of the samples and electromotive force arising over the samples placed in a section of waveguide was measured. Reduction of resistance of the samples was observed with increase in microwave power. More complicated shape of the electromotive force dependence on pulse power was found. It is shown that both effects could be explained by models based on a concept of carrier heating by microwave radiation.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 993-996
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dispersion Law with a Low-Energy Non-Parabolicity for the Charge Carriers in the In_{4}Se_{3} Crystal and Related Effects
    Autorzy:
    Kharkhalis, L.
    Shenderovskii, V.
    Sznajder, M.
    Bercha, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/1791362.pdf
    Data publikacji:
    2009-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.15.Mb
    71.20.-b
    72.30.+q
    Opis:
    The influence of parameters of the dispersion law exhibiting a low-energy non-parabolicity for the $In_{4}Se_{3}$ crystal on the plasma-electric effect occurring in the non-equilibrium plasma of this semiconductor was investigated under the circumstances that a longitudinal plasma wave propagates in its non-equilibrium plasma.
    Źródło:
    Acta Physica Polonica A; 2009, 116, 5; 952-953
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Few-Cycle Laser Pulses: The Carrier-Envelope Phase, Its Role in the THz Emission from Laser-Generated Plasmas and a New Way to Measure It
    Autorzy:
    Kress, M.
    Löffler, T.
    Thomson, M.
    Roskos, H.
    Dörner, R.
    Gimpel, H.
    Zrost, K.
    Ergler, T.
    Moshammer, R.
    Morgner, U.
    Ullrich, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813184.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    42.65.Re
    72.30.+q
    78.47.-p
    Opis:
    Terahertz emission from laser-generated air plasmas has recently been identified as an interesting source for THz radiation. High intensities and a large bandwidth of the THz pulses can be achieved. We briefly review several mechanisms which were employed to generate the quasi-static dipole moment needed for the optical rectification process. This leads us to a discussion of a specific application of THz emission from an air plasma, namely the investigation of the carrier-envelope phase of few-cycle optical pulses. Such pulses of a duration of less than 10 fs induce a spatial charge asymmetry in the plasma directly via non-linear tunneling ionization. The asymmetry, and with it the emission of the THz radiation from the plasma, depend on the carrier-envelope phase, with the consequence that one can determine the phase by measurement of the amplitude and polarity of the THz pulse.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 769-776
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Terahertz Resonant Detection by Plasma Waves in Nanometric Transistors
    Autorzy:
    Teppe, F.
    El Fatimy, A.
    Boubanga, S.
    Knap, W.
    Seliuta, D.
    Valusis, G.
    Chenaud, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813191.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.20.Nr
    71.45.Lr
    72.30.+q
    Opis:
    The plasma waves in gated two-dimensional electron gas have a linear dispersion law, similar to the sound waves. The transistor channel is acting as a resonator cavity for the plasma waves, which can reach frequencies in the THz range for a sufficiently short gate length field effect transistors. A variety of possible applications of field effect transistor operating as a THz device were suggested. In particular, it was shown that the nonlinear properties of plasma oscillations can be utilized for THz tunable detectors. During the last few years THz detection related to plasma wave instabilities in nanometer size field effect transistors was demonstrated experimentally. In this work we review our recent experimental results on the resonant plasma wave detection at cryogenic and room temperatures.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 815-820
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Free-Carrier Plasmons as a Novel Tool in Semiconductor Physics
    Autorzy:
    Szuszkiewicz, W.
    Bardyszewski, W.
    Dingrong, Qian
    Jiaming, Zhang
    Julien, C.
    Balkanski, M.
    Witkowska, B.
    Mycielski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1879491.pdf
    Data publikacji:
    1991-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.45.Gm
    72.30.+q
    75.50.Pp
    Opis:
    It is demonstrated that free-carrier plasmons being well defined collective excitations of the electron gas in the range of small wave vectors can serve as a sensitive tool to investigate the optical processes related to the small momentum transfers. As an example the system HgSe:Fe is analysed both experimentally and theoretically.
    Źródło:
    Acta Physica Polonica A; 1991, 79, 1; 141-144
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Grating Diffraction Effects in the THz Domain
    Autorzy:
    Coutaz, J.-K.
    Garet, F.
    Bonnet, E.
    Tishchenko, A. V.
    Parriaux, O.
    Nazarov, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041624.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    78.47.+p
    72.30.+q
    42.65.Re
    Opis:
    We study the far infrared electromagnetic response of grating devices by THz time-domain spectroscopy. We first show that THz waves are efficiently injected into silicon waveguides using grating couplers. Moreover, changing the waveguide material parameters by white-light illumination allows us to strongly modify the coupling efficiency. Then we demonstrate resonant effects in segmented grating structures that act as perfect mirrors at selected wavelengths even for focused beams. About 10 periods of the grating participate in the phenomenon, nevertheless the resonance frequency width of the device remains narrow. This collection of experiments shows that millimeter-size mock-ups and THz waves can be effectively used to extrapolate the optical response of micron-size actual devices.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 26-37
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Efficient Terahertz Pulse Generation in Laser-Induced Gas Plasmas
    Autorzy:
    Löffler, T.
    Kress, M.
    Thomson, M.
    Roskos, H. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041638.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    42.65.Re
    72.30.+q
    78.47.+p
    Opis:
    In this contribution, we review the development of sources for far-infrared (terahertz) radiation based on laser-generated gas plasmas. We describe several generation mechanisms based on ponderomotive forces, external field screening, and optical second-harmonic biasing. These methods are compared with the standard techniques with respect to the achievable terahertz pulse energy.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 99-108
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Frequency Dependence of Shot Noise in Resonant Diodes under Coherent Tunneling
    Autorzy:
    Aleshkin, V.
    Reggiani, L.
    Rosini, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1179729.pdf
    Data publikacji:
    2005-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.70.+m
    72.20.-i
    72.30.+q
    73.23.Ad
    Opis:
    The current spectral density and the Fano factor of a resonant diode are investigated as a function of frequency up to values just below the inverse of the transit time. We consider the case of coherent tunneling for a symmetric double barrier structure at voltages up to the first current peak at 77 K. At high frequencies the Fano factor is found to become suppressed systematically at a value of 0.25 independently of frequency. This suppression below 0.5 is an indication of coherent against sequential tunneling transport.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 2; 298-303
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Excitation of Deep Defects by Intense Terahertz Radiation
    Autorzy:
    Ganichev, S. D.
    Powiązania:
    https://bibliotekanauki.pl/articles/2011109.pdf
    Data publikacji:
    1999-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.55.-i
    72.20.Ht
    72.40.+w
    72.30.+q
    Opis:
    An analysis is done of the ionization of deep impurity centers by high-intensity terahertz radiation, with photon energies tens of times lower than the impurity ionization energy. Under these conditions, ionization can be described as direct tunneling and phonon-assisted tunneling in which carrier emission is accompanied by defect tunneling in configuration space and electron tunneling in the electric field of the radiation. Within a broad range of intensity, frequency, and temperature, the terahertz electric field of the radiation acts like a static field. For very high frequencies and low temperatures an enhancement of tunneling as compared to static fields was observed. The transition between the quasi-static and the high frequency regime is determined by the tunneling time. For the case of deep impurities this is the time of redistribution of the defect vibrational system which depends strongly on temperature and the impurity structure.
    Źródło:
    Acta Physica Polonica A; 1999, 96, 5; 535-544
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Terahertz Emission from Narrow Gap Semiconductors Photoexcited by Femtosecond Laser Pulses
    Autorzy:
    Adomavičius, R.
    Urbanowicz, A.
    Molis, G.
    Krotkus, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041649.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    42.65.Re
    07.57.Hm
    78.47.+p
    72.30.+q
    Opis:
    Large increase in the emitted terahertz power was observed for p-InAs samples with the p-doping levels of approximately 10$\text{}^{16}$-10$\text{}^{17}$ cm$\text{}^{-3}$. This increase was explained by a large surface depletion layer and an electric-field-induced optical rectification effect in the layer. Terahertz fields radiated by the samples of all three investigated Cd$\text{}_{x}$Hg$\text{}_{1-x}$Te layers was of the same order of magnitude. No azimuthal angle dependence of the radiated signal was detected, which evidences that linear current surge effect is dominating over nonlinear optical rectification. Azimuthal angle and magnetic fields emission witness that it is caused by linear photo-Dember type processes.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 132-136
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Terahertz Emission from the Surfaces of InAs and Other Narrow-Gap Semiconductors
    Autorzy:
    Adomavičius, R.
    Krotkus, A.
    Molis, G.
    Urbanowicz, A.
    Malevich, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813200.pdf
    Data publikacji:
    2008-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    42.65.Re
    07.57.Hm
    78.47.-p
    72.30.+q
    Opis:
    THz pulses were used to investigate carrier dynamics in narrow-gap semiconductors. The measurement of the optically induced THz pulse absorption transients provided important insights into electron energy relaxation in the conduction band. In the second set of experiments, THz generation from the surfaces of various semiconductors was studied and compared. It was found that the most efficient THz emitters are semiconductors with a narrow band gap, large intervalley separation in the conduction band, and low nonparabolicity of the main valley.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 3; 859-862
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Electron Structure of d-Transition Metals and their Alloys on the Basis of EELS Study
    Autorzy:
    Kołodziej, H. B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933515.pdf
    Data publikacji:
    1995-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.30.+q
    79.20.Kz
    61.43.Dq
    71.45.Gm
    78.70.Bj
    Opis:
    Analysis of characteristic electron energy losses in reflection from the surface provides information on electron and band structure of the solid state. Study of transition metals, their alloys (Fe-N, Zn-Ni) and amorphous alloys Fe$\text{}_{78}$Si$\text{}_{9}$B$\text{}_{13}$ show that there are two subsets of electron gas characterized by different oscillation frequency. The presence of independent components of volume plasmons corresponding to s and d electrons is an evidence that despite collectivization both the subsets preserve individual features characteristic of the structure of an isolated atom. From the energy losses the following quantities are determined: the effective mass (μ) for particular electron subsets, the Fermi energy (E$\text{}_{F}$), the band widths (δE) for s and d electrons and contribution of the subsets to the metal conductivity (γ). The obtained results for metals are compared to analogous data for alloys both in crystalline and amorphous phase.
    Źródło:
    Acta Physica Polonica A; 1995, 88, 1; 171-176
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synthesis, Roentgenophase Analysis and Physical Properties of $TlIn_{1-x}Er_xSe_2$ Solid Solutions
    Autorzy:
    Mustafaeva, S.
    Kerimova, E.
    Gasanov, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402129.pdf
    Data publikacji:
    2015-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    71.20.Eh
    71.20.-b
    71.20.Nr
    71.55.-i
    72.15.Eb
    72.15.Rn
    72.20.-i
    72.20.Ee
    72.20.Jv
    72.30.+q
    Opis:
    The results of high-frequency dielectric measurements on obtained $TlIn_{1-x}Er_xSe_2$ single crystals provided an opportunity to determine the mechanisms of dielectric losses and charge transport, and also to evaluate the density of states at the Fermi level; the average time of charge carrier hopping between localized states, average hopping distance, scattering of trap states near the Fermi level; concentration of deep traps.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 4; 697-699
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ultrafast Phenomena in Freestanding LT-GaAs Devices
    Autorzy:
    Marso, M.
    Mikulics, M.
    Adam, R.
    Wu, S. Wu.
    Zheng, X.
    Camara, I.
    Siebe, F.
    Förster, A.
    Güsten, R.
    Kordoš, P.
    Sobolewski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041640.pdf
    Data publikacji:
    2005-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.Jv
    72.40.+w
    78.30.Fs
    85.60.-q
    85.60.Gz
    Opis:
    We report on the fabrication and high-frequency performance of our photodetectors and photomixers based on freestanding low-temperature-grown GaAs. The MBE-grown low-temperature GaAs layers are lifted from the native GaAs substrate and transferred on top of variety of host substrates. The freestanding devices exhibit breakdown electrical fields above 200 kV/cm and dark currents below 3×10$\text{}^{-7}$ A at 100 V bias. Device photoresponse shows 0.55 ps wide electrical transients with voltage amplitudes up to 1.3 V, measured using an electro-optical sampling technique with 100 fs wide laser pulses. Photomixing experiments at 460 GHz yield a 9 times higher output power for the freestanding device on Si/SiO$\text{}_{2}$ host substrate compared to the native substrate.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 1; 109-117
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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