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Wyszukujesz frazę "Lusakowski, J." wg kryterium: Autor


Wyświetlanie 1-37 z 37
Tytuł:
Physics of THz Field-Effect Transistors
Autorzy:
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1505463.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Mf
52.75.-d
Opis:
Field-effect transistors are nowadays considered as possible elements of THz detection and emission systems. Their THz performance is governed by excitations of two-dimensional plasma in the transistor channel. The paper discusses peculiarities of the photon-plasmon coupling mechanism in field-effect transistors and puts it in the perspective of classical investigation of plasma excitations in two-dimensional systems.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 114-116
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Impact Ionization of Shallow Donors on Luminescence in GaAs
Autorzy:
Wysmołek, A.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1932094.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.-m
72.20.Ht
Opis:
Luminescence spectra of n-type molecular beam epitaxial layer and semi-insulating liquid encapsulated Czochralski grown bulk GaAs were measured at liquid helium temperature for zero electric field and for fields which caused impact ionization of shallow donors. Application of the electric field caused a decrease in the luminescence intensity and a broadening of all observed structures. It was found that the electric field changed the luminescence spectrum of the n-type material in a different way than it did in the case of the semi-insulating one. For the n-type sample, an intensity of excitonic lines decreased much more than that of donor-acceptor lines when the electric field grew. A contrary was observed for the semi-insulating sample. An explanation of the result is proposed which takes into account an influence of ionised impurity scattering and localization in fluctuations of the electrostatic potential on the luminescence process.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 261-264
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current-Voltage Characteristic of Semi-Insulating GaAs, with Trap-Filling Effect
Autorzy:
Karpińska, K.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1886537.pdf
Data publikacji:
1991-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.Jv
Opis:
A detailed investigation of current-voltage (I- V)characteristics of semi-insulating GaAs sample was performed in the vicinity of room temperature. The sample with 300 K resistivity of 2 x 10$\text{}^{7}$ Ω cm was supplied with guard-ring electrodes which allowed the elimination of surface currents. The observed characteristics started with an ohmic part which was followed by a superlinear current on voltage dependence. At a threshold voltage V$\text{}_{th}$ which corresponds to the electric field of about 2 kV/cm the current increased abruptly by a few orders of magnitude. The value of V$\text{}_{th}$ increased with the temperature. It is proposed that the observed shape of the I-V curve is caused by the filling of the EL2 level with injected electrons heated by the electric field.
Źródło:
Acta Physica Polonica A; 1991, 79, 2-3; 281-285
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear Coupling of Oscillatory Modes in Current Flow in Semi-Insulating GaAs
Autorzy:
Karpińska, K.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1891273.pdf
Data publikacji:
1991-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.Ht
Opis:
Spontaneous current oscillations in semi-insulating (SI) GaAs sample caused by high electric field domains nucleation were perturbed by modulated illumination. Coupling between domain and photocurrent oscillations leads to quasiperiodic and frequency-locked behaviour. The observed Arnol'd tongues structure follows the Farey tree ordering and agrees with predictions of the circle map theory. We also suggest a possible mechanism responsible for the coupling of the modes.
Źródło:
Acta Physica Polonica A; 1991, 80, 3; 425-428
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractal Dimensions from Chaotic Oscillations in Semi-Insulating GaAs
Autorzy:
Zduniak, A.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1929673.pdf
Data publikacji:
1993-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
72.20.Ht
Opis:
Relaxation and domain current oscillations in undoped semi-insulating GaAs were observed at room temperature for a broad range of voltage applied to a sample. The oscillations were characterized by a reconstruction of an attractor of the system. An analysis of the attractor helped to discriminate between the two likes of oscillations. A transition from one like of oscillations to the other was connected with a chaotization of the current. A chaotic state of the system was analyzed by calculations of fractal dimensions D$\text{}_{q}$ for -0.6 < g < 40 and the f(α) function.
Źródło:
Acta Physica Polonica A; 1993, 84, 3; 575-578
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Autocorrelation Function and Mutual Information from Short Experimental Time Series
Autorzy:
Zduniak, A.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1932093.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
Opis:
A nonlinear dynamics of self-generated current oscillations in semi-insulating GaAs was studied by the reconstruction of an attractor from a short (14500 points) time series. Two methods of choosing of a time constant (τ) for this reconstruction are compared. One of them assumes τ to be an argument of the first zero of the autocorrelation function and the other takes τ as an argument of the first minimum of the mutual information. It is shown that for periodic oscillations both methods are equivalent, but for chaotic ones only the mutual information gives a time constant which does not depend on a time series used for calculations.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 257-260
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Metallic Pattern for Enhancement of a THz Field in a Two-Dimensional Electron Plasma
Autorzy:
Tarkowski, T.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1033104.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
Metamaterials
THz field enhancement
Opis:
A metamaterial in the form of a periodic lattice of split-ring resonators on a GaAs/AlGaAs heterostructure was numerically studied at terahertz frequencies. A finite-difference time-domain algorithm was applied to calculate distribution of the electromagnetic field in the layer positioned at 100 nm below the heterostructure surface where a two-dimensional electron gas typically resides in real structures. The results allowed to determine the resonant frequencies of the metamaterial as well as an enhancement factor of the electric field as a function of the period of the metamaterial's lattice.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 332-334
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron Temperature in Semi-Insulating GaAs for Low Electric Fields
Autorzy:
Zduniak, A.
Łusakowski, J.
Nowak, G.
Powiązania:
https://bibliotekanauki.pl/articles/1923732.pdf
Data publikacji:
1992-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.Ht
Opis:
Heating of electrons by electric fields smaller than that required for generation of domain oscillations was investigated in samples of EL2-rich semi-insulating GaAs. Current-voltage characteristics were measured as a function of temperature between 268 K and 330 K. They exhibit a sublinear shape which is interpreted as a result of an enhanced electron capture on the EL2. The capture rate and the electron temperature as a function of the electric field was determined. A fitting procedure gave the value of electron capture cross-section on the EL2 to be 2.7 × 10$\text{}^{-13}$ cm$\text{}^{2}$ which agrees with literature data.
Źródło:
Acta Physica Polonica A; 1992, 82, 5; 777-780
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conductivity of Optically Excited Electrons in GaAs in Quantizing Magnetic Fields
Autorzy:
Łusakowski, J.
Grynberg, M.
Huant, S.
Powiązania:
https://bibliotekanauki.pl/articles/1876263.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.Hy
72.20.Ht
Opis:
Magnetoconductivity (σ) measurements on an n-type molecular beam epitaxy grown epitaxial layer and on a bulk liquid encapsulated Czochralski grown undoped semi-insulating GaAs samples were performed for magnetic fields (B) up to 21 T at 4.2 K. To enable current measurements in a wide range of B both samples were permanently illuminated with a band-to-band light. It is shown that for sufficiently high magnetic fields σ(B) dependence is the same for both materials. This result underlines a role of scattering by long-range fluctuations of the electrostatic potential in high-quality n-GaAs in quantizing magnetic fields.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 482-486
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Field Induced Localization in Semiinsulating GaAs
Autorzy:
Łusakowski, J.
Merten, R.
Grynberg, M.
Powiązania:
https://bibliotekanauki.pl/articles/1920957.pdf
Data publikacji:
1992-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Jv
72.15.Gd
72.20.Ht
Opis:
Conductivity experiments were carried out on samples of semiinsulating GaAs at liquid helium temperature in magnetic field up to 6 T. During the measurements the samples were persistently illuminated with infrared light which allowed to populate with electrons a part of shallow donor and conduction band states. Current-voltage characteristics showed an abrupt jump of the current at a threshold electric field which is interpreted as a result of impact ionization of electrons bound on shallow donors and in the tail of the bottom of the conduction band. The jump of the current decreases as the magnetic field increases and disappears for a sufficiently high magnetic field B$\text{}_{0}$. The value of B$\text{}_{0}$ grows with growing light intensity. These results are explained by magnetic-field induced localization of electrons on long-range fluctuations of the electrostatic potential. The localization transition was confirmed by the current dependence on temperature measured at different magnetic fields. A peak on these curves was observed. Its position coincides with the temperature above which impact ionization is not observed. A possible mechanism explaining appearance of the peak is presented.
Źródło:
Acta Physica Polonica A; 1992, 82, 4; 551-560
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of Indium Antimonide at Sub-Terahertz and Terahertz Frequencies
Autorzy:
Yavorskiy, D.
Karpierz, K.
Grynberg, M.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1033781.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
THz spectroscopy
InSb THz detector
Opis:
Responsivity of a bulk InSb detector at liquid helium temperature was studied in the frequency range 0.1 THz
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 338-339
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exciton Binding Energy and Oscillator Strength in a Shallow Quantum Well in an External Magnetic Field
Autorzy:
Zięba, P.
Piętka, B.
Łusakowski, J.
Tralle, I.
Powiązania:
https://bibliotekanauki.pl/articles/1402589.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.Ji
75.75.-c
73.21.Fg
62.20.-x
Opis:
We discuss the influence of an external magnetic field on the exciton energy and the exciton oscillator strength in the shallow quantum wells. We include into consideration the Coulomb attraction between electron and hole, which is rarely taken into account. We self-consistently solve the Schrödinger equation to compare the obtained results with the experimental values.
Źródło:
Acta Physica Polonica A; 2015, 128, 2; 237-239
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resonant Plasmon Response of a Periodically Modulated Two-Dimensional Electron Gas
Autorzy:
Sznajder, P.
Piętka, B.
Szczytko, J.
Łusakowski, J.
Bardyszewski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1409611.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.25.Mq
52.40.Db
73.20.-r
71.10.Ca
73.20.Mf
Opis:
We report the theoretical study of the optical response of a periodically modulated two-dimensional electron gas. The density of states is calculated within the first order of the perturbation theory and the effects of the short-range disorder are explained and discussed. We demonstrate that the magnetic field values corresponding to the characteristic narrowing of the density of states width are given by the zeros of the subsequent Laguerre polynomials. The observed increase of the density of states at the edges are interpreted as van Hove singularities. The broadening effects are shown to modify and smear out the observed effects with increasing temperature above 2 K. The plasmon dispersion relation is discussed in terms of the random phase approximation. Small changes in plasmon dispersion relation related to the periodic modulation were predicted.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1090-1092
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local Electric In-Plane Potential Fluctuations in the CdTe/CdMgTe Based Multiple Quantum Wells
Autorzy:
Nogajewski, K.
Karpierz, K.
Łusakowski, J.
Grynberg, M.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1811966.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
72.15.Rn
72.80.Ey
73.21.Fg
Opis:
Unusual features in the magnetophotoconductivity spectra registered under far infrared illumination of the CdTe/CdMgTe based multiple quantum wells, uniformly n-doped are presented. It is shown that each spectrum exhibits one or two peaks of non-symmetrical shape, with position of their maxima dependent on the voltage applied to the sample. The peaks, observed in the configuration of the crossed electric and magnetic fields, are strongly shifted by a relatively weak in-plane electric field - of the order of 10-50 V/cm. Two different approaches to explain the observed influence are presented. Both are based on a two-step process leading to the photoconductivity signal. The first approach assumes that only the process of photon absorption is influenced by the external fields, the second one assumes that only the process of phonon assisted electron transfer from the excited donor state into the conduction band is influenced by the external fields.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1259-1265
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:
Terahertz Generation and Detection by Plasma Waves in Nanometer Gate High Electron Mobility Transistors
Autorzy:
Knap, W.
Łusakowski, J.
Teppe, F.
Dyakonova, N.
Meziani, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2041635.pdf
Data publikacji:
2005-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.-b
73.23.-b
Opis:
The high electron mobility transistors can act as a resonator cavity for the plasma waves that can reach THz frequencies for a nanometer size devices. As was predicted by Dyakonov and Shur in 1993, the steady state of the current flow in a gated 2D electron gas can become unstable leading to the emission of an electromagnetic radiation at the plasma wave frequencies. The theory predicted also that the plasma waves can be used for resonant detection of THz electromagnetic radiation. In the present paper we review our recent experiments on THz emission and detection performed on high electron mobility transistors based on different semiconductor structures: InGaAs/GaAlAs, GaAs/GaAlAs, and Si.
Źródło:
Acta Physica Polonica A; 2005, 107, 1; 82-91
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sub-Terahertz Emission from Field-Effect Transistors
Autorzy:
Yavorskiy, D.
Karpierz, K.
Kopyt, P.
Grynberg, M.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1033125.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
Field-effect transistors
THz emission
Opis:
Several commercially available field-effect GaInAs-based transistors were studied as emitters of electromagnetic radiation. The emitters were tested either at room or at liquid helium temperature. To spectrally analyse emitted radiation, we applied three different experimental techniques: a spectrum analyser with antennas and mixers, a Michelson interferometer and a magnetic-field-tunable InSb detector. We show that the emission consists of a fundamental frequency of 11.5 GHz and its multiple harmonics spanning the emission band up to about 400 GHz. Analysis of the results allows us to suggest that the emission is caused by a Gunn effect and a high harmonics content is related to a pulse-like time dependence of the current.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 335-337
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Photoluminescence of CdTe/CdMgTe Double Quantum Wells with a Two-Dimensional Electron Gas
Autorzy:
Deresz, M.
Wiater, M.
Karczewski, G.
Wojtowicz, T.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1033223.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
CdTe/CdMgTe quantum wells
magnetophotoluminescence
Opis:
Magnetophotoluminescence measurements at liquid helium temperatures were carried out on asymmetric double quantum wells based on CdTe/CdMgTe heterostructures. Due to doping with shallow iodine donors, a two-dimensional electron gas was present in the quantum wells. The samples studied differed with the quantum well widths and doping level. We show a resemblance of the luminescence to results obtained on single quantum wells which suggests that in samples studied the quantum wells are not strongly coupled.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 390-392
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Γ₆ → Γ₈ Free-to-Bound Transitions in Acceptor δ-Doped Single Heterostructure - Theoretical Analysis
Autorzy:
Buczko, R.
Łusakowski, J.
Friedland, K.
Hey, R.
Ploog, K.
Powiązania:
https://bibliotekanauki.pl/articles/1811919.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
78.67.De
Opis:
A theoretical analysis was carried out of an optical transition observed in high-quality GaAs/AlGaAs heterostructures δ-doped with shallow acceptors. The transition involves a 2D electron and a 3D acceptor-localized hole. The wave functions of a bulk Be acceptor were calculated within the spherical model with both the s-like and d-like parts of the envelope taken into account. The electron envelope wave functions resulted from self-consistent calculations of the electrostatic potential and were dependent on the 2D electron concentration, $n_s$. We show that: (i) including the d-like part of the acceptor envelope relaxes the selection rules of free-to-bound transitions at k=0;(ii) in the magnetic field, the selection rules depend on the number of the electron Landau level;(iii) the ratio of the intensity of the strongest transitions in both circular polarizations is essentially different from 3:1, and strongly depends on $n_s$. These results show that a description that neglects the d-like part of the acceptor envelope is both qualitatively and quantitatively unjustified.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1079-1083
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectroscopy of Be Acceptor Ground State in GaAs/AlGaAs Heterostructure
Autorzy:
Łusakowski, J.
Buczko, R.
Sakowicz, M.
Friedland, K. J.
Hey, R.
Ploog, K.
Powiązania:
https://bibliotekanauki.pl/articles/2047378.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
78.67.De
Opis:
Photoluminescence measurements were carried out on Be δ-doped GaAs/Al$\text{}_{0.33}$Ga$\text{}_{0.67}$As heterostructure at 1.6 K in magnetic fields (B) up to 4 T. Luminescence originating from recombination of a two-dimensional electron gas and photoexcited holes localized on Be acceptors was analyzed. The degree of circular polarization (γ$\text{}_{C}$) of the luminescence from fully occupied Landau levels was determined as a function of B and the two-dimensional electron gas concentration, n$\text{}_{s}$. At B constant,γ$\text{}_{C}$ decreased with the increase in n$\text{}_{s}$. The intensity of the optical transition considered was calculated with taking into account s- and d-like parts of the acceptor envelope function. It is shown that the presence of the d-like part explains the observed γ$\text{}_{C}$(n$\text{}_{s}$) dependence quantitatively. This shows that polarization spectroscopy on acceptorδ-doped heterostructures enables one to test experimentally the contribution of the L>0 component of the envelope in a shallow acceptor description.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 209-213
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-Ohmic Conductivity of High Resistivity CdTe
Autorzy:
Łusakowski, J.
Szczytkowski, J.
Szadkowski, K.
Kamińska, E.
Piotrowska, A.
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1933850.pdf
Data publikacji:
1995-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.80.-r
Opis:
Conductivity measurements were carried out at room temperature on samples of nominally undoped Bridgman, bulk crystals and MBE-grown layers of CdTe. The samples were equipped with indium contacts which made it possible to determine the voltage distribution along the path of the current flow. The results show that for both types of CdTe almost all of the applied voltage drops in the vicinity of the positively biased contact. The resistance of the samples was shown not to depend on the distance between the pads. The results agree with predictions of model of current injection into semiconductors with deep traps.
Źródło:
Acta Physica Polonica A; 1995, 88, 4; 803-806
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanism of Radiation Coupling to Plasma Wave Field Effect Transistor Sub-THz Detectors
Autorzy:
Sakowicz, M.
Łusakowski, J.
Karpierz, K.
Grynberg, M.
Gwarek, W.
Knap, W.
Boubanga, S.
Powiązania:
https://bibliotekanauki.pl/articles/1811983.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
84.40.Ba
52.40.Fd
85.30.Tv
07.57.Kp
Opis:
Detection of 100 GHz and 285 GHz electromagnetic radiation by GaAs/AlGaAs field effect transistors with the gate length of 150 nm was investigated at 300 K as a function of the angleαbetween the direction of linear polarization of the radiation and the symmetry axis of the field effect transistors. The angular dependence of the detected signal was found to be Acos²(α-α₀)+C. A response of the transistor chip (including bonding wires and the substrate) to the radiation was numerically simulated. Calculations confirmed experimentally observed dependences and allowed to investigate the role of bonding wires and contact pads in coupling of the radiation to the transistor channel.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1337-1342
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Interface-Induced Disorder on Classical and Quantum Conductivity of CdTe:IN Epitaxial Layers
Autorzy:
Łusakowski, J.
Karpierz, K.
Grynberg, M.
Karczewski, G.
Wojtowicz, T.
Contreras, S.
Callen, O.
Powiązania:
https://bibliotekanauki.pl/articles/1968369.pdf
Data publikacji:
1997-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Jt
73.61.Ga
Opis:
An influence of disorder originated from the substratelayer interface on electrical properties of CdTe:In layers was investigated by means of the Hall effect and magnetoresistance measurements at low temperatures. An estimation of a scattering rate due to interface-induced disorder is given. Characteristic features of a magnetic field dependence of magnetoresistance are explained by an influence of quantum interference of scattered electron waves both in the hopping and the free electron conductivity regimes.
Źródło:
Acta Physica Polonica A; 1997, 92, 5; 911-914
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Field Induced Redistribution of Exciton-Polariton Density on Confined Modes
Autorzy:
Piętka, B.
Szczytko, J.
Łusakowski, J.
Nardin, G.
Léger, Y.
Morier-Genoud, F.
Deveaud-Plédran, B.
Powiązania:
https://bibliotekanauki.pl/articles/1409612.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.36.+c
42.55.Sa
71.35.-y
71.35.Ji
78.20.Ls
Opis:
The influence of magnetic field on confined exciton-polariton modes inside a semiconductor microcavity is discussed. The three-dimensional confinement for exciton-polaritons is achieved by the mesa structures confining the photonic part of polaritons. We observe a strong increase of the polariton emission intensity and we argue that this effect is due to the change of the oscillator strength of the excitonic component of polaritons and the change of the excitonic content in polariton state as the magnetic field increases.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1093-1095
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
THz Time Domain Spectroscopy of Thin Gold Layers on GaAs
Autorzy:
Szczytko, J.
Adomavicius, R.
Papis, E.
Barańska, A.
Wawro, A.
Krotkus, A.
Piętka, B.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1417930.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.66.Bz
78.68.+m
Opis:
Thin layers of Au with the thickness of several nanometers were prepared on a semi-insulating GaAs substrate. The layers' thickness was determined by ellipsometry. THz time-domain spectroscopy was applied to determine a complex index of refraction of thin Au layers. The obtained results allow for a more precise modeling of the performance of semiconductor devices at THz frequencies.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1118-1120
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Magnetic Field Effects on Plasma Wave THz Detection in Field-Effect Transistors
Autorzy:
Boubanga-Tombet, S.
Nogajewski, K.
Teppe, F.
Knap, W.
Karpierz, K.
Łusakowski, J.
Grynberg, M.
Dyakonov, M.
Powiązania:
https://bibliotekanauki.pl/articles/1791357.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.57.Kp
84.40.x
85.30.Tv
85.35.p
73.20.Mf
Opis:
Experiments on terahertz radiation detection with InGaAs/InAlAs field-effect transistor in quantizing magnetic field are reported. We observed oscillations of the photovoltaic signal analogous to the Shubnikov-de Haas oscillations, as well as their strong enhancement at the cyclotron resonance conditions. The results are described quantitatively within the frame of a theory which takes into account a new source of nonlinearity related to the Landau quantization of the conduction band.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 939-940
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoplasmons in a High Electron Mobility GaAs/AlGaAs Heterostructure
Autorzy:
Białek, M.
Karpierz, K.
Piętka, B.
Grynberg, M.
Łusakowski, J.
Czapkiewicz, M.
Fronc, K.
Wróbel, J.
Umansky, V.
Powiązania:
https://bibliotekanauki.pl/articles/1409613.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.Mf
Opis:
We have observed a multimode spectrum of magnetoplasmons in the Hall bars processed on a high electron mobility GaAs/AlGaAs heterostructure. We have found that the dispersion relation of these excitation follows square root dependence. Calculated wavelength of the fundamental magnetoplasmon mode fits to the width of sample.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1096-1098
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mobility of Holes in Nanometer Ge-on-Si p-Type Metal-Oxide-Semiconductor Field-Effect Transistors at Low Temperatures
Autorzy:
Grigelionis, I.
Fobelets, K.
Vincent, B.
Mitard, J.
De Jaeger, B.
Simoen, E.
Hoffman, T.
Yavorskiy, D.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1492960.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.My
85.30.Tv
Opis:
We investigated magnetoresistance of p-type Ge-on-Si metal-oxide-semiconductor field-effect transistors in order to determine the hole mobility μ as a function of the gate polarization $(V_{G})$. Measurements were carried out at 4.2 K and magnetic fields up to 10 T. The signal measured was proportional to the derivative of the transistor resistance with respect to $V_{G}$. To determine the hole mobility we developed a method to treat the measured signal which is based on a numerical solution of a differential equation resulting from the theoretical description of the experimental procedure. As a result, we obtained a non-monotonic $μ(V_{G})$ dependence which is a characteristic feature of the carrier transport in gated two-dimensional structures.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 933-935
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Terahertz Photovoltaic Response of Si-MOSFETs: Spin Related Effect
Autorzy:
Videlier, H.
Dyakonova, N.
Teppe, F.
Consejo, C.
Chenaud, B.
Knap, W.
Lusakowski, J.
Tomaszewski, D.
Marczewski, J.
Grabiec, P.
Powiązania:
https://bibliotekanauki.pl/articles/1492958.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.30.Tv
Opis:
We report on investigations of photovoltaic response of Si-MOSFETs subjected to terahertz radiation in high magnetic fields. Then a DC drain-to-source voltage is developed that shows singularities in magnetic fields corresponding to paramagnetic resonance conditions. These singularities are investigated as a function of incident frequency, temperature and two-dimensional carrier density. We tentatively attribute these resonances to spin transitions of the electrons bound to Si dopants and discuss the possible physical mechanism of the photovoltaic signal generation.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 927-929
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Terahertz Response of a Point Contact Based on CdTe/CdMgTe Quantum Well in Magnetic Field
Autorzy:
Grigelionis, I.
Białek, M.
Grynberg, M.
Czapkiewicz, M.
Kolkovskiy, V.
Wiater, M.
Wojciechowski, T.
Wróbel, J.
Wojtowicz, T.
But, D.
Knap, W.
Łusakowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1409358.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.30.Hi
73.20.Mf
Opis:
A photoresponse at THz frequencies of a quantum point contact fabricated on a CdTe/CdMgTe quantum well was studied at low temperatures as a function of magnetic field. The spectra show a structure which was interpreted as resulting from the cyclotron resonance and magnetoplasmon excitations. The wavelength of the fundamental magnetoplasmon mode was found to be about 2 μm which coincides with one of dimensions of the point contact. We also discuss the possibility of coupling of magnetoplasmon modes to shallow impurity transitions in the quantum well.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1069-1072
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Terahertz Detection by the Entire Channel of High Electron Mobility Transistors
Autorzy:
Sakowicz, M.
Łusakowski, J.
Karpierz, K.
Knap, W.
Grynberg, M.
Köhler, K.
Valusis, G.
Gołaszewska, K.
Kamińska, E.
Piotrowska, A.
Caban, P.
Strupiński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1811985.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.75.+a
78.20.Ls
85.30.Tv
07.57.Kp
Opis:
GaAs/AlGaAs and GaN/AlGaN high electron mobility transistors were used as detectors of THz electromagnetic radiation at liquid helium temperatures. Application of high magnetic fields led to the Shubnikov-de Haas oscillations of the detection signal. Measurements carried out with a simultaneous modulation of the intensity of the incident THz beam and the transistor gate voltage showed that the detection signal is determined by the electron plasma both in the gated and ungated parts of the transistor channel. This result is of importance for understanding the physical mechanism of the detection in high electron mobility transistors and for development of a proper theoretical description of this process.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1343-1348
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrical and Structural Properties of Ohmic Contacts to n-Type and High Resistivity CdTe
Autorzy:
Kamińska, E.
Piotrowska, A.
Guziewicz, M.
Gierlotka, S.
Papis, E.
Łusakowski, J.
Szadkowski, K.
Kwiatkowski, S.
Dietl, T.
Grabecki, G.
Jaroszyński, J.
Karczewski, G.
Zakrzewski, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/1873052.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.40.Ns
Opis:
The interaction between CdTe and In during the formation of an ohmic contact has been investigated. Emphasis is placed on the study of the effect of thermally induced sublimation of cadmium on electrical properties of contacts. Presented results prove the effectiveness of cap annealing and rapid thermal processing in fabrication of improved ohmic contacts with limited Cd losses during the contacting procedure.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 411-414
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raman Spectroscopy of Co-Doped ZnO Bulk Crystals
Autorzy:
Szuszkiewicz, W.
Morhange, J. F.
Gołacki, Z.
Łusakowski, A.
Schumm, M.
Geurts, J.
Powiązania:
https://bibliotekanauki.pl/articles/2047700.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
78.30.Fs
Opis:
Low-temperature Raman spectra of a bulk mixed crystal Zn$\text{}_{1-x}$Co$\text{}_{x}$O (x = 0.016) are shown and analyzed. Besides the common modes of the ZnO host lattice, electronic transitions related to the presence of Co$\text{}^{2+}$ ions at the Zn sites are observed. In spite of the low Co concentration the presence of collective excitations corresponding to Co and CoO precipitates is also revealed.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 363-368
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Specific Heat of Pb$\text{}_{1-x}$Eu$\text{}_{x}$Te
Autorzy:
Górska, M.
Łusakowski, A.
Jędrzejczak, A.
Gołacki, Z.
Anderson, J. R.
Balci, H.
Powiązania:
https://bibliotekanauki.pl/articles/2038143.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.-d
75.40.Cx
Opis:
The temperature dependence of the magnetic specific heat was studied experimentally and theoretically in the semimagnetic semiconductor Pb$\text{}_{1-x}$Eu$\text{}_{x}$Te for x=0.027 and x=0.073, over the temperature range from 0.5 K to 15 K, in magnetic fields up to 2 T. In zero magnetic field at about 2 K there was a broad maximum in the magnetic specific heat, which was much higher than that predicted by the model of superexchange interaction between nearest neighbors; the maximum values increased with magnetic field. The experimental data were analyzed in the framework of a model which takes into account the spin splitting of the ground state of a single Eu2+ ion in the presence of local lattice distortions in the Pb$\text{}_{1-x}$Eu$\text{}_{x}$Te mixed crystal. The model describes well the experimental data, especially for lower x-values, where the contribution from singlets dominates.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 631-636
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Field Magnetization of Sn$\text{}_{1-x}$Gd$\text{}_{x}$Te
Autorzy:
Górska, M.
Anderson, J. R.
Wolters, C.
Łusakowski, A.
Story, T.
Gołacki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1969093.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.20.Ck
75.30.Et
Opis:
The magnetization of p-type Sn$\text{}_{1-x}$Gd$\text{}_{x}$Te with x up to 0.045 and the hole concentration, p, varying from 2.7 to 8.3×10$\text{}^{20}$ cm$\text{}^{-3}$ has been measured in magnetic fields up to 27 T, at the temperatures 4.2 and 1.3 K. The data were fitted to a magnetization equation with single-ion and pair terms. From comparison of the exchange parameters determined from the high-field magnetization with those previously obtained from the high-temperature magnetic susceptibility it was found that in samples with p>5×10$\text{}^{20}$ cm$\text{}^{-3}$ the exchange was of a short-range type, while in samples with a lower carrier concentration the long-range exchange mechanism was observed.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 347-350
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Is the Magnetism of HgSe:Fe Clearly Understood?
Autorzy:
Dybko, K.
Łusakowski, A.
Kossut, J.
Arciszewska, M.
vd Linden, P. J. E. M.
Wittlin, A.
Perenboom, J. A. A. J.
Mycielski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1931952.pdf
Data publikacji:
1995-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Hx
75.20.Hr
Opis:
The high magnetic field magnetization measurements of low composition Hg$\text{}_{1-x}$Fe$\text{}_{x}$Se (0.0002 < x < 0.003) at temperatures ranging from 1.6 K to 40 K and in magnetic fields up to 20 T are reported. The magnetization in a sample containing only Fe$\text{}^{3+}$ ions (x = 0.0002) is described by the Brillouin function (j = 5/2). The magnetization in the sample codoped with Ga, containing only Fe$\text{}^{2+}$ is well described in the model of isolated Fe$\text{}^{2+}$ ions. The latter model takes into account the tetrahedral crystal field, the spin-orbit interaction and the Zeeman term. On the other hand, the magnetization of sample with both Fe$\text{}^{3+}$ and Fe$\text{}^{2+}$ present simultaneously (x = 0.003) is shown to be different from a simple additive superposition of the contributions due to Fe$\text{}^{3+}$ and Fe$\text{}^{2+}$ subsystems. The possible origin of this discrepancy is discussed.
Źródło:
Acta Physica Polonica A; 1995, 87, 1; 193-196
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low-Frequency Raman Spectrum οf Bulk $Zn_{0.984}Co_{0.016}O$ Crystal
Autorzy:
Szuszkiewicz, W.
Łusakowski, A.
Morhange, J.
Gołacki, Z.
Arciszewska, M.
Brodowska, B.
Kanehisa, M.
Klepka, M.
Dobrowolski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1807848.pdf
Data publikacji:
2009-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
78.30.Fs
Opis:
The influence of possible presence of $Co^{2+}$ ion pairs in a bulk $Zn_{1-x}Co_{x}O$ mixed crystal on the low-frequency part of the Raman spectrum is discussed. Two effects can be taken into account in the theoretical considerations when analyzing the energy level scheme corresponding to Co ions. The first is a local lattice deformation in the vicinity of $Co^{2+}$ ion due to a presence of the second ion, smaller than the host ZnO lattice cation. Such deformation creates a trigonal field, which can only slightly modify the energy levels of $Co^{2+}$ ion. The second effect, which results from an antiferromagnetic superexchange interaction between two $Co^{2+}$ ions is responsible for a new set of energy levels. The Raman data taken at low temperature on the sample corresponding to the composition x = 0.016 demonstrated the presence of two structures at about 6 $cm^{-1}$ and 13 $cm^{-1}$. These structures may be interpreted as electronic transitions between the ground state and the first excited state of a single $Co^{2+}$ ion in the substitution site of ZnO lattice and as a similar transition for $Co^{2+}$ ion pair, respectively.
Źródło:
Acta Physica Polonica A; 2009, 116, 1; 103-106
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-37 z 37

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