Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "quantum" wg kryterium: Wszystkie pola

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 96
Tytuł:
Collective Encoding of Quantum Information in a Quantum Dot Register
Autorzy:
Grodecka, A.
Machnikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/2046914.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
63.20.Kr
03.67.Pp
Opis:
We define the collective logical quantum bit as a state on an array of 2, 4, and 8 quantum dots. We show that such an array can be controlled with less phonon-induced pure dephasing than a single dot. We calculate the dephasing accompanying a single-qubit operation on the collective logical qubit by means of perturbative method describing the open system evolution under arbitrary driving.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 195-200
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Confinement in InAs/GaAs Systems with Self-Assembled Quantum Dots Grown Using In-Flush Technique
Autorzy:
Molas, M.
Kuldová, K.
Borysiuk, J.
Wasilewski, Z.
Babiński, A.
Powiązania:
https://bibliotekanauki.pl/articles/2048050.pdf
Data publikacji:
2011-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Cr
78.67.Hc
Opis:
The effect of In-flush technique application to the MBE-grown structure with self-assembled quantum dots is investigated in this work. The microphotoluminescence from structures with the InAs/GaAs dots grown with and without the In-flush has been investigated. We focus our attention on "not fully developed" dots, which can be clearly distinguished in the spectrum. The dots have also been identified in the transmission electron microscopy analysis of the structures. The In-flush does not influence a broad energy range of those features. Instead we have found that the anisotropic exchange energy splitting of neutral excitons confined in those in the structure grown with In-flush is substantially lower that the splitting in the structure with no In-flush. This observation confirms that the In-flush leads not only to better uniformity of self-assembled quantum dots but also to reduction of lateral potential, anisotropy, which is believed to result in the neutral exciton splitting.
Źródło:
Acta Physica Polonica A; 2011, 119, 5; 624-626
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coupling of Quantum Dots with Quantum Wells in a System Based on (Cd,Zn,Mg)Te
Autorzy:
Połczyńska, K.
Janik, E.
Kossacki, P.
Pacuski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1033157.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
78.67.Hc
73.21.La
78.67.-n
Opis:
Coupled low dimensional structures have potential applications in quantum computing and spintronics. Using molecular beam epitaxy we fabricated three kinds of systems of coupled quantum wells and quantum dots with different energy order: wells at higher energy than dots, resonant structures, and dots at higher energy than wells. By analysis of photoluminescence and reflectivity spectra, we conclude that there is a possibility of effective carrier tunneling between structures, which opens possibility of subsequent testing of spin transfer efficiency.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 369-371
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oscillator Strengths of Quantum Transitions in Spherical Quantum Dot $GaAs$/$Al_{x}Ga_{1-x}As$/$GaAs$/$Al_{x}Ga_{1-x}As$ with On-Center Donor Impurity
Autorzy:
Holovatsky, V.
Bernik, I.
Voitsekhivska, O.
Powiązania:
https://bibliotekanauki.pl/articles/1207322.pdf
Data publikacji:
2014-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.La
78.67.Hc
71.55.-i
Opis:
The investigation of the electron and hole energies and probability densities is performed for the cases with and without the donor hydrogenic impurity placed into the centre of quantum dot quantum well structures with different thicknesses of layers. The oscillator strengths of intra- and interband quantum transitions in $GaAs$/$Al_{x}Ga_{1-x}As$ core/shell/well/shell spherical quantum dot with ionized on-center donor impurity are estimated. The oscillator strengths of quantum transitions non-monotonously depend on the width of the layers due to the different location of carriers. The optimal geometrical parameters of the nanostructure are estimated for the possibility of multicolor light emission based on interband quantum transitions.
Źródło:
Acta Physica Polonica A; 2014, 125, 1; 93-97
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Four-Wave Mixing Spectroscopy of Quantum Dot Molecules
Autorzy:
Sitek, A.
Machnikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/2047371.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
78.47.+p
Opis:
We study theoretically the nonlinear four-wave mixing response of an ensemble of coupled pairs of quantum dots (quantum dot molecules). We discuss the shape of the echo signal depending on the parameters of the ensemble: the statistics of transition energies and the degree of size correlations between the dots forming the molecules.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 167-172
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nano-Optics on Individual Quantum Objects - From Single to Coupled Semiconductor Quantum Dots
Autorzy:
Bacher, G.
Schömig, H.
Welsch, M. K.
Scheibner, M.
Seufert, J.
Obert, M.
Forchel, A.
Maksimov, A. A.
Zaitsev, S.
Kulakovskii, V. D.
Powiązania:
https://bibliotekanauki.pl/articles/2035563.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
75.50.Pp
73.21.La
Opis:
Some recent highlights of our optical studies on single and coupled semiconductor quantum dots are reviewed. In the first part, we concentrate on the role of spins and spin-spin interaction in nonmagnetic and magnetic single quantum dots. In the case of strictly resonant excitation of the ground state in self-assembled CdSe/ZnSe quantum dots, we find an exciton spin relaxation time, which exceeds the recombination lifetime significantly. Linear polarization has to be used for these experiments, as the electron-hole exchange interaction lifts the spin degeneracy and the eigenstates are linear combinations of spin-up and spin-down excitons. In a magnetic quantum dot, the exchange interaction between carrier spins and the spins of magnetic ions is shown to be responsible for giant magneto-optical effects. We demonstrate the formation of zero-dimensional magnetic polarons and we succeeded in measuring the magnetization on a scale of a few nanometers using the characteristic photoluminescence signal of individual quantum dots as experimental monitor. The second part is devoted to pairs of single quantum dots. On one hand, single exciton tunneling within an individual quantum dot pair is demonstrated studying single pairs of vertically correlated strain-induced and self-organized quantum dots. On the other hand, we show that in a pair of lithographically defined single dots with strongly different g-factors the energy spacing between the dot ground states can be tuned in an external magnetic field by about 10 meV, giving access to a controlled coupling between two individual quantum dots.
Źródło:
Acta Physica Polonica A; 2002, 102, 4-5; 475-494
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin in CdTe/ZnTe Quantum Dot: Its Potential for Information Storage
Autorzy:
Kazimierczuk, T.
Powiązania:
https://bibliotekanauki.pl/articles/1807600.pdf
Data publikacji:
2009-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
78.55.Et
Opis:
We present a selection of our studies on CdTe/ZnTe quantum dots considered as spin qubits. Discussed experiments are related to processes of spin reading, writing and evolution. We show that CdTe/ZnTe system is well suitable for studying effects important for optical quantum computing on single spins.
Źródło:
Acta Physica Polonica A; 2009, 116, S; S-13-S-18
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carrier Trapping in a Quantum Dash: Optical Signatures
Autorzy:
Kaczmarkiewicz, P.
Machnikowski, P.
Kuhn, T.
Powiązania:
https://bibliotekanauki.pl/articles/1403618.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
73.21.La
Opis:
We theoretically study the optical properties and the electronic structure of highly elongated quantum dots (quantum dashes) and show how geometrical fluctuations affect the excitonic spectrum of the system. The dependence of the absorption intensities on the geometrical properties (depth and length) of the trapping center in a quantum dash is analyzed and the dependence of the degree of the linear polarization on these geometrical parameters is studied.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 997-1000
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Spectroscopy of Quantum Dots in High Magnetic Fields
Autorzy:
Babiński, A.
Powiązania:
https://bibliotekanauki.pl/articles/2046951.pdf
Data publikacji:
2006-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
78.55.Cr
75.75.+a
Opis:
Optical spectroscopy measurements of single InAs/GaAs self-assembled quantum dots have been performed. The multiexcitonic emission from the s-, p-, and d-shells of a single dot is observed and investigated in magnetic field up to 28 T. The Zeeman splitting of the s-shell excitons has been found to depend on the dot morphology. While the energy-splitting in flat (2 nm height) dots linearly increases with magnetic field, its significant non-linearity is observed for larger in size, tall (4 nm height) dots. The effect of magnetic field on the orbital motion of carriers in dots has also been investigated. It has been found that the modified Fock-Darwin pattern explains the observed evolution of the emission from highly-excited single tall quantum dot.
Źródło:
Acta Physica Polonica A; 2006, 110, 3; 275-286
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emission of Self-Assembled CdTe/ZnTe Quantum Dot Samples with Different Cap Thickness
Autorzy:
Nowak, S.
Powiązania:
https://bibliotekanauki.pl/articles/1791338.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
78.67.Hc
Opis:
Photoluminescence measurements on CdTe/ZeTe self-assembled quantum dot samples with different cap thickness values (18-110nm) were performed at 1.8 K at varying excitation levels. The shape of macrophotoluminescence spectra did not altered notably with the excitation power. The spectra exhibited interference fringes related to the total barrier thickness. Simulation of the fringes confirmed the barrier thickness determined during the growth. The minimal amplitude of the fringes was observed for the cap thickness corresponding approximately to a quarter of the emission wavelength in the barrier material. Maximum emission intensity occurred for the largest thickness of the cap, i.e., 110 nm. We attribute this result to the influence of the surface recombination centers.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 890-892
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charging Effects in Self-Assembled CdTe Quantum Dots
Autorzy:
Kłopotowski, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/1492785.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
32.60.+i
71.35.Pq
71.55.Gs
Opis:
In this review, we summarize our achievements in controlling and understanding the charging effects in single self-assembled CdTe quantum dots. We start with analysis of the single dot emission spectrum. For excitation densities small enough to ensure only s-shell recombination, we find that for all dots (also those reported by other groups) the same transition sequence is observed. Namely, the neutral exciton recombination has the highest energy while charged exciton and biexciton transitions are redshifted. This observation remains in a stark contrast to self-assembled InGaAs dots, where charged complexes may appear also on the high energy side of the neutral exciton. We explain the universality of the transition sequence assuming domination of the Coulomb correlations over direct, single particle interactions. Furthermore, through measurement of the recombination rates, we gain access to electron and hole wave functions and their redistributions upon changing the dot occupancy. We find that the electron wave function is rather stiff, while the hole wave function is rather soft owing to enhanced correlations in the valence band. We then corroborate these conclusions with the Stark spectroscopy, where we analyze energy shifts due to electric field imposed on dots embedded in a field effect or diode structure. Finally, we use these structures to obtain controllable tuning of the charge state. We discuss different approaches to this task and find the best tuning efficiency for a structure with enhanced valence band confinement.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 819-829
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Excitonic Magnetoabsorption of Cylindrical Quantum Disks
Autorzy:
Schillak, P.
Czajkowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1492888.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
73.22.Dj
73.21.La
71.35.Ji
Opis:
We show how to compute the optical functions (the complex magnetosusceptibility, dielectric function, magnetoreflection) for semiconductor quantum disks exposed to a uniform magnetic field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of nanostructure excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. The confinement potentials are taken as step-like both in the z and in-plane directions. Numerical calculations have been performed for $In_{0.55}Al_{0.45}As$ (disk)/$Al_{0.35}Ga_{0.65}As$ (barrier) and InP/GaP disks and the results are in a good agreement with the available experimental data.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 888-890
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Collective Spontaneous Emission from a System of Quantum Dots
Autorzy:
Abdussalam, W.
Machnikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1403617.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
42.50.Ct
03.65.Yz
Opis:
We study the spontaneous emission from a regular lateral array or a randomly distributed ensemble of quantum dots under strong excitation (full inversion) conditions. We focus on the similarities and differences between the cases of random and regular arrangement of the dots and show that there is very little difference between the evolution of luminescence in these two cases, both for identical dots and for a realistically inhomogeneously broadened ensemble. This means that the enhanced emission or superradiance effect is not due to accidental clustering of pairs of dots. Moreover, we point out that observation of an enhanced emission under weak excitation does not prove that true superradiance will develop in a fully inverted system.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 994-996
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sub-Nanosecond Phase Recovery in Quantum-Dot Semiconductor Optical Amplifiers
Autorzy:
Abedi, K.
Taleb, H.
Powiązania:
https://bibliotekanauki.pl/articles/1399957.pdf
Data publikacji:
2013-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
78.67.-n
78.67.Hc
Opis:
In this paper, optimal design of a pumping scheme for achieving the best gain and phase response in quntum-dot semiconductor optical amplifiers is investigated. For the first time, the dynamic response of the quntum-dot semiconductor optical amplifier is evaluated under three different pumping schemes, known as optical pumping, electrical pumping, and electro-optical pumping. Simulation results show that the shortest gain recovery time in quntum-dot semiconductor optical amplifiers can be achieved under the electrical pumping scheme. However, under the optical pumping and electro-optical pumping schemes, the quntum-dot semiconductor optical amplifier represents a shorter phase recovery compared to the electrical pumping scheme. We found that a sub-nanosecond phase recovery in the quntum-dot semiconductor optical amplifier can be achieved under the OP and electro-optical pumping schemes, which can never be achieved under the electrical pumping, because of the slow carrier dynamics of the carrier reservoir. Also, it was found that the gain recovery process in an optically pumped quntum-dot semiconductor optical amplifier can be significantly accelerated at cryogenic temperatures. This result demonstrates the superiorities of the optical pumping scheme over the electrical pumping and electro-optical pumping schemes at low temperatures, where both the gain and phase recovery times of an optically pumped quantum-dot semiconductor optical amplifier are drastically decreased.
Źródło:
Acta Physica Polonica A; 2013, 123, 2; 407-410
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantized Absorption Strength of Multi-Exciton Quantum Dots
Autorzy:
Wójcik, K.
Grodecka, A.
Wójs, A.
Powiązania:
https://bibliotekanauki.pl/articles/2047045.pdf
Data publikacji:
2006-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.22.-f
78.67.Hc
71.35.-y
Opis:
Energy and absorption/recombination spectra of up to two electron-hole pairs confined in a spherical quantum dot are studied numerically as a function of dot radius (i.e., confinement volume). The transition between fermionic and bosonic behavior of the confined excitons is identified in coincidence with enhancement of low-energy absorption strength.
Źródło:
Acta Physica Polonica A; 2006, 110, 3; 423-428
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 96

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies