Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl

Refine search results

Journals help

  1. 47 Acta Physica Polonica A

Years help

  1. 2 2017

  2. 2 2014

  3. 4 2013

  4. 2 2012

  5. 7 2011

More...
Authors help

  1. 47 Kossacki P.

  2. 28 Golnik A.

  3. 23 Gaj J.

  4. 17 Goryca M.

  5. 14 Kazimierczuk T.

More...
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 47

Number of results on page
first rewind previous Page / 3 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 3 next fast forward last
1
Content available remote

Magnetic Ions in Studies of Semiconductor Quantum Well Structures

100%
Kossacki P.
Acta Physica Polonica A
|
1998
|
vol. 94
|
issue 2
147-154
EN
A few aspects of a relation between magnetic properties of Mn ion system and electronic states confined in CdTe based quantum wells are discussed. It is shown that the influence of the magnetic fluctuations on the states confined in the quantum well results in the reduction of the relative valence band offset with temperature. Also the decrease in the effective Zeeman splitting is observed by a modulation technique at high temperatures and is explained in terms of the modification of the selection rules for an exciton localised in thermal fluctuations. For the p-doped samples the giant Zeeman splitting is used to tune the polarization of a hole gas by a small magnetic field. The "competition-like" relation between the oscillator strength of exciton (X) and positive trion (X^{+}) is proved experimentally.
2
Publication available in full text mode
Content available

Spectroscopic Studies of Charged Excitons

100%
Kossacki P.
Acta Physica Polonica A
|
2001
|
vol. 100
|
issue 2
237-248
EN
A brief review is given of optical experiments related to creation and recombination of charged excitons. Their results are analyzed in terms of a simple three-particle free trion model. It is shown that the simple model explains well such results as temperature variation of lifetime and absorption intensity or photoluminescence line shape and a decrease in absorption oscillator strength per carrier with increasing carrier concentration. The range of applicability of the simple model is examined and found to be limited by two factors: disorder-induced localization and many-body interactions occurring and high carrier sheet concentrations (of order of 10^{11} cm^{-2}).
3
Content available remote

Magnetoresistance of n-CdTe in the "Persistent" State

64%
Kossacki P., Karpierz K.
Acta Physica Polonica A
|
1993
|
vol. 84
|
issue 4
737-740
EN
In this paper we present results of measurements done on photoexcited carriers in high purity n-CdTe at liquid helium temperature. The photocurrent under near band gap illumination was measured, as well as the long term (≈ 15 hours) photoconductive decay after switching off the light. The transverse magnetoresistance was measured in high magnetic fields in two cases: 1) under external illumination, 2) in the "persistent" state after ≈ 15 h of photocurrent decay. It was shown that in high magnetic fields this magnetoresistance exhibits a quadratic dependence on magnetic field (Δρ/ρ ≈ B^{2}) in both cases.
4
Content available remote

Coupling of Quantum Dots with Quantum Wells in a System Based on (Cd,Zn,Mg)Te

52%
Połczyńska K., Janik E., Kossacki P., Pacuski W.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 2
369-371
EN
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.
5
Content available remote

Single-Mode-Fiber-Based Mach-Zehnder Interferometer Setup for Correlation Measurements for Single CdTe/ZnTe Quantum Dots

52%
Rodek A., Kazimierczuk T., Starzyk P., Kossacki P.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 2
379-382
EN
We report on design and construction of a single-mode-fiber-based Mach-Zehnder interferometer system for measuring single photon indistinguishability from quantum dots emitting in visible spectrum (630±50 nm). The performance of the instrument was tested for its efficiency and usability in single-photon correlation measurements in a proposed experimental setup.
6
Content available remote

Spin-Wave Excitations and Fluctuations of the Exchange Interaction in Amorphous Fe_{1-x}Zr_{x} Alloys

52%
Kossacki P., Stobiecki T., Szymczak H.
Acta Physica Polonica A
|
1993
|
vol. 83
|
issue 6
785-791
EN
Detailed magnetization measurements were performed on amorphous Fe_{1-x}Zr_{x} alloys with 0.14 ≤ x ≤ 0.48 at temperatures ranging from 4.2 K to the Curie temperature in external magnetic field up to 5 T. An analysis of the experimental data reveals that' the fluctuations of the exchange integral resulting from the structural disorder give important contribution to the thermal demagnetization and high-field susceptibility of Fe-rich alloys. For Zr-rich alloys the effect of fluctuations of the exchange integral is negligible and thermal demagnetization is described in terms of spin-wave excitations. No Stoner single-particle excitations were observed for alloys with x > 0.14.
7
Content available remote

Temperature of a Single Mn Atom in a CdTe Quantum Dot

52%
Papierska J., Goryca M., Wojnar P., Kossacki P.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 5
899-900
EN
In this work we present a study of the temperature of the single magnetic atom embedded in a semiconductor quantum dot versus excitation power and magnetic field. This temperature is defined by the thermal distribution of spin states of single Mn ion, and results from its interaction with the neighborhood. This temperature was found to be much higher than the temperature of the thermal bath. Its dependence on the excitation power and magnetic field is discussed.
8
Publication available in full text mode
Content available

Time-Resolved Studies of Excitonic Dynamics in a Wide II-VI Quantum Well by a Femtosecond Pump-Probe Reflectivity

46%
Trajnerowicz A., Golnik A., Kossacki P., Pacuski W., Wojtowicz T.
Acta Physica Polonica A
|
2006
|
vol. 110
|
issue 3
395-401
EN
We present time-dependent reflectance spectra of wide (Cd,Mn)Te/(Cd,Mg)Te quantum wells. Interactions between excitons, trions, and carriers are studied for exciton densities up to 10^{11} cm^{-2}. The resonant excitation at different excitonic lines is analyzed.
9
Content available remote

Photoluminescence Dynamics of CdSe Quantum Dot with Single Mn^{2+} Ion under Modulated Excitation

46%
Pilat M., Goryca M., Smoleński T., Pacuski W., Kossacki P.
|
|
vol. 126
|
issue 5
1212-1214
EN
A quantum dot with a single magnetic ion is a perfect model system to investigate spin dynamics of a magnetic ion embedded in semiconductor matrix. In this work we present results of spin dynamics studies of Mn^{2+} ion embedded in CdSe quantum dot, performed under modulated excitation of the dot. In particular, the relaxation time of the Mn^{2+} ion in high magnetic field was determined.
10
Content available remote

Magnetooptical Analysis of Interface Mixing in Pulsed Laser Evaporation and Epitaxy Grown CdTe/Cd_{0.9}Mn_{0.1}Te Multiple Quantum Well and Superlattice

46%
Lewalski A., Nguyen K., Kossacki P., Gaj J., Dubowski J.
Acta Physica Polonica A
|
1993
|
vol. 84
|
issue 3
571-574
EN
A recently proposed magnetooptical method of determination of interface mixing was applied to CdTe/CdMnTe superstructures grown by pulsed laser evaporation and epitaxy. Diffusion length were found ≈ 5 Å for a multiple quantum well and > 15 Å for a superlattice. Ranges of Mn mole fractions and well width values enabling efficient application of the method were determined.
11
Publication available in full text mode
Content available

Femtosecond Dynamics of Neutral and Charged Exciton Absorption in Cd_{1-x}Mn_xTe Quantum Well

40%
Płochocka P., Kossacki P., Maślana W., Radzewicz C., Gaj J., Cibert J., Tatarenko S.
|
|
issue 4-5
679-686
EN
We present a study of time-dependent transmission spectra of a modulation-doped Cd_{1-x}Mn_xTe/Cd_{1-y-z}Zn_yMg_zTe quantum well with variable hole gas concentration. We study the influence of pump pulses on excitonic absorption in subpicosecond time scale. A spectrally broad probe pulse of duration of 40 femtoseconds was used to record the absorption spectra at controlled delay. Studies of temporal evolution of exciton energies revealed coherence decay of linearly polarized excitons and thermalization of non-equilibrium exciton states. We found that a characteristic timescale for thermalization of non-equilibrium populations of photocreated excitons is between 0.8 and 3.6 ps. The timescale of this process depends on the hole concentration in quantum well: for higher hole concentration the decay is faster. Long-lived photo-induced magnetization accompanied by heating of the magnetic system was also observed.
12
Content available remote

Signatures of p-Shell Electron g-Factor in s-Shell Emission of CdTe/ZnTe Quantum Dots

40%
Kazimierczuk T., Goryca M., Wojnar P., Golnik A., Nawrocki M., Kossacki P.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 5
874-876
EN
We analyze the photoluminescence of excitonic complexes containing p-shell electron in the magnetic field in the Faraday configuration. We demonstrate that despite the p-shell electron is not involved directly in the recombination process, its g-factor influences the emission spectrum. We found that in the case of CdTe/ZnTe quantum dots the p-shell electron is significantly less affected by the magnetic field than s-shell electron in the same dot.
13
Content available remote

Cold and Hot Excitons in CdMnTe/CdMgTe Quantum Wells in Strong Excitation Regime and External Magnetic Field

40%
Trajnerowicz A., Golnik A., Kossacki P., Bardyszewski W., Wiater M., Karczewski G., Wojtowicz T.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 5
849-851
EN
Systematic studies of neutral heavy-hole excitonic line energy changes in a strong excitation regime were carried out by means of a pump-probe method for quantum wells containing a 2D gas of free holes. Energy shift of X_{e1hh1} line was analyzed for different excitation energies at fixed delay between pump and probe pulses, also under external magnetic field. It was observed that this shift depends not only on the density of created excitons but also directly on the pump energy. In co-polarization configuration for excitation energy below an absorption resonance the energetic blue shift rises linearly with the elevated exciton density (localized excitons are created). For energies slightly above the resonance, the blue shift diminishes dramatically in spite of high exciton density present (delocalized excitons are created). Model absorption calculations are in qualitative agreement with the experimental data.
14
Content available remote

Inter-Dot Coupling in a Self-Assembled Quantum Dot System

40%
Kazimierczuk T., Nowak S., Suffczyński J., Wojnar P., Golnik A., Gaj J., Kossacki P.
Acta Physica Polonica A
|
2007
|
vol. 112
|
issue 2
321-324
EN
We present studies of resonant excitation of self-assembled CdTe/ZnTe quantum dots. Photoluminescence excitation measurements revealed existence of sharp resonances, common for photoluminescence lines attributed to different quantum dot charge states. We conclude from the ensemble of photoluminescence and photoluminescence excitation results that we observe energy transfer in coupled quantum dot pairs.
15
Publication available in full text mode
Content available

Long Decays of Excitonic Photoluminescence from CdTe/ZnTe Individual Quantum Dots

40%
Piechal B., Suffczyński J., Trajnerowicz A., Goryca M., Kossacki P., Golnik A., Gaj J.
Acta Physica Polonica A
|
2005
|
vol. 108
|
issue 5
831-836
EN
We present time-resolved micro-photoluminescence study of self-assembled CdTe/ZnTe quantum dots. In addition to the fast radiative decay of the exciton, we observe long components, being of the order of a few nanoseconds. We observe that long decays are present for neutral exciton lines as well as on the biexciton ones. The temperature dependent measurements reveal the non-monotonic behaviour. We find also that the long decays are not mono-exponential. We conclude that the dark exciton states cannot be treated as the only source of long decays in the luminescence. We propose other possible explanation, which is the slowing of luminescence by carrier trapping in high energy states in quantum dots and barriers.
16
Publication available in full text mode
Content available

Excitonic Giant Zeeman Effect in Wide Gap Diluted Magnetic Semiconductors Based on ZnO and GaN

40%
Pacuski W., Ferrand D., Kossacki P., Marcet S., Cibert J., Gaj J., Golnik A.
Acta Physica Polonica A
|
2006
|
vol. 110
|
issue 3
303-309
EN
We present a theoretical description of the excitonic giant Zeeman effect observed in wide gap diluted magnetic semiconductors (Zn,Co)O and (Ga,Mn)N. In these materials, A and B excitons present quite complex energy shifts and change of oscillator strengths under magnetic field. These features can be well reproduced using an excitonic Hamiltonian, taking into account ion-carrier exchange, wurtzite trigonal crystal field, spin-orbit and electron-hole exchange interactions.
17
Content available remote

MBE Growth and Magnetooptical Properties of (Zn,Co)Te Layers

40%
Papaj M., Kobak J., Rousset J., Janik E., Golnik A., Kossacki P., Pacuski W.
Acta Physica Polonica A
|
2012
|
vol. 122
|
issue 6
1010-1011
EN
We report on epitaxial growth of diluted magnetic semiconductor (Zn,Co)Te. Reflectivity spectra reveal excitonic transition which split under magnetic field due to giant Zeeman effect. Magnetooptical effects can be described using literature data.
18
Content available remote

Magnetoluminescence of a CdTe Quantum Dot with a Single Manganese Ion in Voigt Configuration

40%
Koperski M., Goryca M., Kazimierczuk T., Kossacki P., Wojnar P., Gaj J.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 5
618-620
EN
We present a study of the neutral exciton and negative trion recombination spectra of an individual CdTe quantum dot with a single manganese ion, in magnetic field measured in the Voigt configuration. We describe experimental results and compare with a theoretical model. The quantitative agreement between the model and the experiment allows us to determine separately the electron g-factor.
19
Content available remote

Numerical Rate Equation Approach to Picosecond Charge State Dynamics in CdTe/ZnTe Quantum Dots

40%
Koperski M., Kazimierczuk T., Goryca M., Wojnar P., Golnik A., Kossacki P., Gaj J.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 5
893-895
EN
The rate equation is used for description of photoluminescence dynamics after pulsed excitation of various states of quantum dots. The picosecond dynamics of averaged charge state of quantum dot is described. We compare our simulations with the experiment and come up with the conclusion that probability of carrier capture weakly depends on quantum dot charge state and that electrons and holes are captured non-synchronously.
20
Content available remote

Anisotropic Exchange Interaction between p-Shell Electron and s-Shell Hole in CdTe/ZnTe Quantum Dots

40%
Kazimierczuk T., Golnik A., Goryca M., Wojnar P., Gaj J., Kossacki P.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 5
882-884
EN
We study electron-hole exchange interaction in a single CdTe/ZnTe quantum dot by polarization-resolved photoluminescence measurements. We focus on recombination of excitonic states involving p-shell electrons: X^{2-} and XX^-. Recombination lines of X^{2-} and XX^- states exhibit fine structure, which can be consistently explained within a model with four parameters δ_{i}^{αβ} representing strength of iso- and anisotropic parts of interaction between s-hole and s- or p-electron.
first rewind previous Page / 3 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.