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Wyszukujesz frazę "71.70.Ej" wg kryterium: Temat


Tytuł:
Band Mixing Effects in Quantum Well Magnetoexcitons
Autorzy:
Wysocki, R.
Bardyszewski, W.
Schoser, S.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1968450.pdf
Data publikacji:
1997-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
71.35.Ji
Opis:
The influence of intersubband mixing in quantum wells of semiconductors with zinc-blende structure is studied both experimentally and theoretically. A multiband magnetoexciton model is described which takes into account k∙p mixing between valence subbands and the effective Coulomb interaction for an arbitrary confinement potential shape. Theoretical results reproduce very well the photoluminescence excitation spectra of GaAs/AlGaAs single quantum wells of various widths. In particular, the characteristic avoided crossing between the lowest light-hole exciton Landau level and excited heavy-hole exciton Landau level occurring at σ¯ polarization is accurately described by our theory.
Źródło:
Acta Physica Polonica A; 1997, 92, 5; 1067-1071
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stark and Zeeman Effects in Nd$\text{}_{2}$Fe$\text{}_{14}$B and Pr$\text{}_{2}$Fe$\text{}_{14}$B Intermetallics
Autorzy:
Radwański, R. J.
Franse, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/1945558.pdf
Data publikacji:
1996-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
75.10.Dg
Opis:
The energy level scheme of the Nd$\text{}^{3+}$ and Pr$\text{}^{3+}$ ions in ferromagnetic Nd$\text{}_{2}$Fe$\text{}_{14}$B and Pr$\text{}_{2}$Fe$\text{}_{14}$B intermetallic compounds was evaluated on the basis of all known experiments. In calculations the effect of charge (Stark effect) and spin-dependent (Zeeman effect) interactions were taken into account by means of the crystal-field and molecular-field approximation, respectively. The derived energy level scheme is associated with the removal of the degeneracy of the lowest multiplet given by Hund's rules, i.e. $\text{}^{4}$I $\text{}_{9}\text{}_{/}\text{}_{2}$ (Nd$\text{}^{3+}$) and $\text{}^{3}$H$\text{}_{4}$ (Pr$\text{}^{3+}$). The revealed low-energy electronic structure (<25 meV = 200 cm$\text{}^{-1}$) is associated with many-electron states of the RE$\text{}^{3+}$ ions. Magnetic and electronic properties resulting from this fine structure are compared with all known experimental results. The localized crystal electric field levels exist also in Nd$\text{}_{2}$CuO$\text{}_{4}$, an ionic compound which by doping with Ce becomes high-T$\text{}_{c}$ superconductor, indicating the formation of crystal electric field states independently on the metallic or ionic state.
Źródło:
Acta Physica Polonica A; 1996, 90, 1; 223-232
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of an Electric Field on Fine Properties of III-V and II-VI Quantum Dots Systems
Autorzy:
Kowalik, K.
Krebs, O.
Kudelski, A.
Golnik, A.
Lemaître, A.
Senellart, P.
Karczewski, G.
Kossut, J.
Gaj, J.
Voisin, P.
Powiązania:
https://bibliotekanauki.pl/articles/2038219.pdf
Data publikacji:
2004-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
71.70.Ej
Opis:
We investigate the influence of an electric field on the optical properties of single quantum dots. For sample made of III-V compounds micron-size electro-optical structures were produced in order to apply an electric field in the dot plane. For several individual dots lines significant variations of the anisotropic exchange splitting with the field were observed. On sample made of II-VI compounds we demonstrate the influence of electric field fluctuations on the luminescence of a single quantum dot.
Źródło:
Acta Physica Polonica A; 2004, 106, 2; 177-184
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibronic Effects in EPR Spectra of (NH$\text{}_{4}$)$\text{}_{2}$Cu(BeF$\text{}_{4}$)$\text{}_{2}$·6H$\text{}_{2}$0 Single Crystal
Autorzy:
Hoffmann, S.
Gomółka-Marciniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/1929355.pdf
Data publikacji:
1993-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.30.-v
71.70.Ej
Opis:
Angular variations of the g-factors and linewidth value were recorded at X-band, at room temperature, and at 77 K. The temperature dependence of the g-factors was measured along the principal g-tensor axes in the temperature range from 4.2 K to 300 K. The rigid lattice g-factors at 4.2 K are: g$\text{}_{z}$ = 2.428, g$\text{}_{y}$ = 2.138, and g$\text{}_{x}$ = 2.058. The g$\text{}_{x}$ value very slowly increases linearly on heating, whereas g$\text{}_{z}$ and g$\text{}_{y}$ nonlinearly tend towards their average value. This is a typical behaviour of Cu(II) EPR in Tutton salt crystals, however the g(T) dependence is much less pronounced in (NH$\text{}_{4}$)$\text{}_{2}$Cu(BeF$\text{}_{4}$)$\text{}_{2}$·6H$\text{}_{2}$0 as compared to the Cu(II) doped salts. The results are described in terms of the two vibronic coupling models of the strong Jahn-Teller effect. It is shown that the models are not adequate to describe the vibronic g-factor behaviour in paramagnetic Cu(II) crystals which is attributed to the cooperative Jahn-Teller effect existing in these crystals.
Źródło:
Acta Physica Polonica A; 1993, 83, 6; 817-830
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal-Field Interactions in $RPd_2Al_3$ Intermetallics (R = Pr, Nd, Sm, and U)
Autorzy:
Radwanski, R.
Nalecz, D.
Ropka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1374347.pdf
Data publikacji:
2014-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
75.10.Dg
Opis:
Magnetic and electronic properties of $NdPd_2Al_3$ have been nicely described with the $Nd^{3+}$ ions within the crystal-field theory revealing that all Nd atoms equally contribute to the temperature dependence of the paramagnetic susceptibility and of the heat capacity with the λ-peak. We consistently described paramagnetic and magnetically-ordered state. The fine electronic structure of the $Nd^{3+}$ ion nicely correlates with the electronic structure of the $U^{3+}$ ion in $UPd_2Al_3$ giving strong evidence for the trivalent uranium state in the isostructural heavy-fermion superconductor $UPd_2Al_3$.
Źródło:
Acta Physica Polonica A; 2014, 126, 4a; A-32-A-35
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Submilimeter Magnetospectroscopy on ZnFeSe
Autorzy:
Krevet, R.
Kempf, P.
Von Ortenberg, M.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1887118.pdf
Data publikacji:
1991-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.30.Fs
71.70.Ej
Opis:
We report FIR laser spectroscopy study of Zn$\text{}_{1-x}$Fe$\text{}_{x}$Se (x < 0.06) Semimagnetic Semiconductor at the temperature range of 2-26 K and magnetic fields up to 18T.
Źródło:
Acta Physica Polonica A; 1991, 79, 2-3; 381-383
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:
Importance of the Spin-Orbit Coupling for 3d-Ion Compounds: the Case of NiO
Autorzy:
Radwański, R. J.
Ropka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2013984.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.20.Hr
71.70.Ej
Opis:
The orbital and spin moment of the Ni$\text{}^{2+}$ ion in NiO has been calculated at 0 K to be 0.54 μ$\text{}_{B}$ and 1.99 μ$\text{}_{B}$ respectively. Such large orbital moment, more than 20% of the total moment of 2.53 μ$\text{}_{B}$, proves the need for the "unquenching" of the orbital moment in compounds containing 3d ions. It turns out that the spin-orbit coupling is indispensable for description of magnetic and electronic properties of 3d-ion compounds.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 963-965
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Spin-Orbit Scattering on the Electrical Resistivity of Disordered Materials
Autorzy:
Spisak, B.
Paja, A.
Powiązania:
https://bibliotekanauki.pl/articles/2011166.pdf
Data publikacji:
1999-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
72.15.Cz
Opis:
The spin-orbit scattering of charge carriers is considered as an additional contribution to the potential scattering. The expressions for the effective cross-section and the relaxation time for disordered media are calculated. The results for the Coulomb screened potential are presented and compared with available experimental data.
Źródło:
Acta Physica Polonica A; 1999, 96, 6; 751-758
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Self-Assembled CdTe/ZnTe Quantum Dots
Autorzy:
Kowalik, K.
Kudelski, A.
Golnik, A.
Gaj, J. A.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/2035754.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.67.Hc
71.70.Ej
Opis:
We present microluminescence investigations of self-assembled CdTe/ZnTe quantum dots. The dots proprieties resulting from our studies are: values of optical in-plane anisotropy parameters (electron - heavy hole exchange splitting and orientation of anisotropy) and value of effective Lande factor. Parameters giving information about in-plane anisotropy possess random distribution of values with the exchange splitting from 0 to 240 μeV. The effective Lande factor values for our dots are around g$\text{}^{*}$=-3.2 with a scatter of about 18%. Some PL lines exhibit sudden jumps of energetic position, related to variation of the charge state in their neighborhood.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 539-544
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:
Application of Generalized Pair Approximation to Diluted Magnetic Semiconductor Quantum Structures
Autorzy:
Bednarski, H.
Cisowski, J.
Portal, J. C.
Powiązania:
https://bibliotekanauki.pl/articles/1947680.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
75.30.Et
Opis:
Analysing the d-d interaction in diluted magnetic semiconductor quantum structures, we used our generalized pair approximation which permits to take into account the real spatial distribution of the magnetic ions in diluted magnetic semiconductor layers close to the nonmagnetic quantum well. We subsequently applied our approach to calculate the Zeeman splittings in the CdTe/Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te quantum structures with x=5 and 7.5% and we obtained a good agreement with the experimental results.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 723-726
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific Heat of Cr-Based Semimagnetic Semiconductors
Autorzy:
Twardowski, A.
Eggenkamp, P.
Mac, W.
Swagten, H. J. M.
Demianiuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1929660.pdf
Data publikacji:
1993-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
71.70.Ch
71.70.Ej
Opis:
Specific heat of ZnCrSe and ZnCrS was measured for 1.5 < T < 10 K and B < 3 T. The data were interpreted using "crystal field model" taking into account tetrahedral crystal field, tetragonal Jahn-Teller distortion and spin-orbit interaction.
Źródło:
Acta Physica Polonica A; 1993, 84, 3; 563-565
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electric Dipole and Current Induced Spin Resonances of Shallow Donor in ZnO
Autorzy:
Michaluk, E.
Błoniarz, J.
Pabich, M.
Wilamowski, Z.
Mycielski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2046940.pdf
Data publikacji:
2006-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Gs
76.30.-v
71.70.Ej
Opis:
In this paper we present our observation of electric dipole spin resonance and current induced spin resonance in ZnO bulk crystals, both effects result from spin-orbit coupling. Electric dipole spin resonance originates from admixture of spin state due to spin-orbit interaction which leads to probability of spin-flip caused by electric component of microwave field. In current induced spin resonance phenomenon the electric component of microwave field induces electron motion leading to mean ac spin-orbit field that acts on electron spin. Spin-orbit interaction can be described in terms of the Rashba field, an effective magnetic field that induce spin resonance. In contrast to magnetic and electric dipole spin resonances the current induced resonance is characterized by dispersive-like line shape.
Źródło:
Acta Physica Polonica A; 2006, 110, 2; 263-270
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron-Phonon Interaction as a Mechanism of Phase Transition in the $CuInP_{2}S_{6}$ Crystal
Autorzy:
Bercha, D.
Bercha, S.
Glukhov, K.
Sznajder, M.
Powiązania:
https://bibliotekanauki.pl/articles/1376070.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.60.Cn
71.15.Mb
71.70.Ej
Opis:
Studies on the phases of $CuInP_{2}S_{6}$ crystal exhibiting phase transitions of the order-disorder type are performed. A possibility for the cooperative Jahn-Teller effect to occur in this crystal is analyzed. For this purpose, the procedure of constructing the potential energy matrix is generalized for the case of crystal and it is illustrated by the construction of the adiabatic potentials for $Γ_{5}$-$Γ_{5}$ vibronic coupling for the proto- and paraelectric phases of $CuInP_{2}S_{6}$. The structure of the obtained potentials is analyzed together with the discussion on the appearance of spontaneous polarization in this crystal.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1143-1145
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Absorption Studies of the Sulphur Donor in GaSb
Autorzy:
Kaczor, P.
Gerrits, A. M.
Dobaczewski, L.
Kaliński, Z.
Wittlin, A.
Powiązania:
https://bibliotekanauki.pl/articles/1873018.pdf
Data publikacji:
1995-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
71.70.Ej
78.50.Ge
Opis:
The shallow-deep bistability of the sulphur-related DX centre in GaSb is demonstrated. After photoexcitation of the defect with the near-band gap light the metastable inter-donor transition in the far infrared can be observed. This observation allowed us to evaluate the polaron effective mass and polaron coupling constant for the material.
Źródło:
Acta Physica Polonica A; 1995, 87, 2; 399-402
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Localization of Excitons in the Wetting Layer Accompanying Self-Assembled InAs/GaAs Quantum Dots
Autorzy:
Babinski, A.
Raymond, S.
Wasilewski, Z.
Lapointe, J.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2038091.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.Pq
71.35.Ji
71.70.Ej
Opis:
A wetting layer is a narrow, highly strained quantum well, which accompanies quantum dots grown in Stranski-Krastanow mode. Its importance for a full description of the quantum dots properties has recently been pointed out. It has been shown for example that excitons can be localized by potential fluctuations in the wetting layer. This is equivalent to the formation of "natural" quantum dots in the WL. Excitonic emission from the single dots formed in the wetting layer accompanying the InAs/GaAs self-assembled quantum dots has been investigated in a high magnetic field (up to 23 T). Quadruplet splitting of the investigated emission line has been observed. The attribution of the emission line to the recombination of negatively charged exciton is discussed.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 547-552
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometry of the $\text{}^4T_{2g}$ Excited State in $Cs_2SiF_6:Mn^{4+}$
Autorzy:
Reisz, A.
Avram, C.
Powiązania:
https://bibliotekanauki.pl/articles/1815472.pdf
Data publikacji:
2007-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
63.20.Kr
63.70.+h
Opis:
The aim of this paper is to calculate the equilibrium displacements of the $\text{}^4T_{2g}$ potential surface minimum from the ground state along the $a_{1g}$ and $e_g$ Jahn-Teller active modes for the octahedral $[MnF_6]^{2-}$ cluster obtained by doping $Mn^{4+}$ ions in $Cs_2SiF_6$ host crystal. The equilibrium displacements in normal and Cartesian coordinates were estimated from force constants of $[MnF_6]^{2-}$ cluster and Huang-Rhys factors associated with the Jahn-Teller stabilization energy. A net equatorial expansion and an axial stretching of the geometry of the $[MnF_6]_{2-}$ cluster in first $\text{}^4T_{2g}$ excited state, as combined effect of the $a_{1g}$ and $e_g$ displacements, were demonstrated.
Źródło:
Acta Physica Polonica A; 2007, 112, 5; 829-833
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strain Induced k-Linear Spin Splitting in III-V Semiconductors
Autorzy:
Skierkowski, A.
Majewski, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/2047724.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Fk
71.15.Rf
71.70.Ej
71.55.Eq
Opis:
We present theoretical studies of the linear-k strain induced spin splitting of the conduction band in the zinc-blende semiconductors. The studies are based on ab initio calculations performed within the density functional theory with non-scalar relativistic effects fully taken into account. This permits one to construct effective Hamiltonian for the strain induced linear-k spin splitting of the zinc-blende semiconductors. This Hamiltonian reproduces fully the structure of the strain induced linear-k spin splitting and generalizes previously introduced and commonly used effective Hamiltonian.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 455-460
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Field Dependence of Spin Lifetimes in Wurtzite Materials
Autorzy:
Majewski, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/2044501.pdf
Data publikacji:
2005-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Mb
71.20.Nr
71.70.Ej
71.70.Fk
Opis:
We present first-principles calculations of the zero field spin splitting of energy bands in wurtzite materials. Our calculations reveal that the huge electric fields originating from strong piezo- and pyroelecric character of nitrides do not increase the spin splitting of bands in nitride heterostructures. This implicates long spin lifetimes in quantum structures based on these materials and weak possibility of tuning with external electric field.
Źródło:
Acta Physica Polonica A; 2005, 108, 5; 777-780
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interplay Between Spin-Orbit Coupling and Structural Deformations in Heavy Transition-Metal Oxides with Tetrahedral Coordination
Autorzy:
Forte, F.
Guerra, D.
Avella, A.
Autieri, C.
Romano, A.
Noce, C.
Powiązania:
https://bibliotekanauki.pl/articles/1030491.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
75.25.Dk
71.27.+a
Opis:
We analyze the effects of a large spin-orbit coupling on the magnetic state of a d¹ transition-metal ion located in a tetrahedral environment. While in the ideal tetrahedral symmetry the spin-orbit coupling acts only as a perturbation on the atomic energy levels set by the crystal-field splitting, we demonstrate that its effects are strongly enhanced in the case of distorted geometries. In particular, we consider the specific case in which the tetrahedron is compressed along the z direction, and show that, by increasing the degree of flattening, a large spin-orbit interaction (i) can induce a substantial anisotropic, unquenched orbital momentum and (ii) can affect the hierarchy of the lowest energy levels that are involved in the magnetic exchange.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 394-397
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Gd Impurities on the Physical Properties of Half-Metallic Ferromagnet $Co_2MnSi$
Autorzy:
Grasin, R.
Vinteler, E.
Bezergheanu, A.
Rusu, C.
Pacurariu, R.
Deac, I.
Tetean, R.
Powiązania:
https://bibliotekanauki.pl/articles/1535753.pdf
Data publikacji:
2010-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
71.55.Ak
73.20.Hb
Opis:
In this paper we report our experimental and theoretical studies on the effect of Gd impurity on the physical properties of the Heusler half-metallic ferromagnet $Co_2MnSi$. The analysis of the band structures of the doped alloy shows that the half-metallic properties are completely conserved if Gd substitutes Mn atoms. This effect is not determined by the spin-orbit interaction, but through the coupling between the R(4f) spin with the Mn(3d) itinerant electron spins. We evaluate the strength of such a coupling by calculating, in an ab initio fashion, the total energy of $Co_{16}GdMn_7Si_8$ compound for a parallel and antiparallel f-d coupling. The obtained magnetic moments of Co or Mn sites are in good agreement with the experimental ones.
Źródło:
Acta Physica Polonica A; 2010, 118, 4; 648-651
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Magnetoresistance in Multi-Level Quantum Wells
Autorzy:
Averkiev, N. S.
Golub, L. A.
Pikus, G. A.
Powiązania:
https://bibliotekanauki.pl/articles/1969000.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
71.70.Ej
73.20.Fz
Opis:
Effect of intensive interlevel transitions in quantum well and strong spin-orbit interaction on weak localization is considered. Anomalous magnetoresistance in classically weak fields is calculated for p-type quantum wells based on A$\text{}_{3}$B$\text{}_{5}$ semiconductors. It is shown that the sign of magnetoresistance changes with varying doping level and the role of the intersubband transitions in weak localization effects depends dramatically on a view of the scattering potential.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 229-234
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Field Ionization of Shallow Acceptors
Autorzy:
Dargys, A.
Žurauskas, S.
Žurauskienė, N.
Powiązania:
https://bibliotekanauki.pl/articles/1861465.pdf
Data publikacji:
1993-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
73.20.Hb
79.70.+q
Opis:
Experimental studies on hole tunneling from the substitutional boron impurity into degenerate valence band of silicon single crystals are presented. The results are interpreted within the framework of acceptor ground state quartet splitting into the Kramers doublet due to presence of random strains and electric field in the lattice.
Źródło:
Acta Physica Polonica A; 1993, 84, 4; 629-632
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Study of Spin Lifetimes in [110] Strained GaAs
Autorzy:
Skierkowski, A.
Majewski, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/2047003.pdf
Data publikacji:
2006-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
71.70.Fk
71.70.Ej
72.25.Rb
Opis:
We present first-principles studies of the zero field spin splitting of conduction band in [110] strained GaAs that determine spin lifetimes in semiconductors. Our calculations reveal strong anisotropy of the linear-k spin splitting in the (110) plane of the Brillouin zone and very minor in the (001) plane. This provides a qualitative understanding of the difference in the spin lifetimes in the GaAs/AlAs heterostructures grown along [100] and [110] crystallographic directions.
Źródło:
Acta Physica Polonica A; 2006, 110, 3; 353-358
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relation between Structure and Magnetic Properties of Microstructured $PrAlO_3$
Autorzy:
Andrzejewski, B.
Pawlak, D.
Klimczuk, T.
Turczyński, S.
Powiązania:
https://bibliotekanauki.pl/articles/1429107.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.60.Ej
71.70.Ej
75.50.-y
75.70.Tj
Opis:
The magnetic properties of both the praseodymium-aluminium perovskite $PrAlO_3$ crystal and its microstructured version in the form of a $PrAlO_3-PrAl_{11}O_{18}$ eutectic have been investigated. It is shown that R\overline{3}c → Imma 205 K first-order and Imma → C 2/m near 150 K second-order phase transitions in a $PrAlO_3$ single crystal are suppressed after structuring the material and embedding it in a $PrAl_{11}O_{18}$ matrix. This behavior is related to the $PrAl_{11}O_{18}$ matrix, which mechanically hinders expansion of the microrods and in this way suppresses the phase transitions.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1315-1317
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetocaloric effect in CsDy(MoO₄)₂
Autorzy:
Tarasenko, R.
Tkáč, V.
Orendáčová, A.
Orendáč, M.
Sechovský, V.
Feher, A.
Powiązania:
https://bibliotekanauki.pl/articles/1050647.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Sg
75.30.Gw
71.70.Ej
Opis:
CsDy(MoO₄)₂ belongs to the family of binary alkaline rare-earth molybdates, with detectable low-temperature structural phase transitions, caused by the cooperative Jahn-Teller effect. Magnetocaloric studies of a single crystal of CsDy(MoO₄)₂ have been performed in the temperature range from 2 K to 18 K in magnetic fields up to 7 T applied along the crystallographic a axis. The maximum value of the isothermal entropy change is about 8 J/(kgK) and was achieved already in the fields above 2 T. The observed results suggest that the studied system can be used as a magnetic refrigerant at helium temperatures.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 414-416
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Quantum Transport through an Asymmetric Aharonov-Bohm Ring with Rashba Spin-Orbit Interaction
Autorzy:
Baltateanu, D.
Powiązania:
https://bibliotekanauki.pl/articles/1492777.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.23.-b
71.70.Ej
73.23.Ad
Opis:
The transmission amplitude through an asymmetric Aharonov-Bohm ring is derived analytically, in the presence of the Rashba spin-orbit interaction. For this purpose, one resorts to the transfer matrix method. The conductance is established in terms of the Landauer formalism and it is analyzed for different values of the asymmetry and ring-lead coupling parameters. A theoretical proposal to use the asymmetric ring like a spin filtering device is discussed, by an adequate tuning of the Aharonov-Bohm and Aharonov-Casher phases (via the magnetic field and the Rashba parameter).
Źródło:
Acta Physica Polonica A; 2011, 120, 6; 1047-1055
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zero Field Spin Splitting in GaN/AlGaN Heterostructures Probed by the Weak Antilocalization
Autorzy:
Dybko, K.
Siekacz, M.
Skierbiszewski, C.
Powiązania:
https://bibliotekanauki.pl/articles/1811927.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
73.43.Qt
73.20.Fz
Opis:
We present the magnetoconductivity measurements of a high mobility two-dimensional electron gas confined at GaN/AlGaN interface. The sensitive measurements of low field conductivity revealed both quantum corrections, the weak localization and antilocalization effects. It indicates the importance of the spin-orbit coupling in this wide band gap material. The analysis of the data provided the information about the temperature dependence of the dephasing time and total spin-orbit relaxation time. The conduction band spin splitting energy amounts to 0.23 meV and 0.35 meV at electron densities $2.2×10^{12} cm^{-2}$ and $5.7×10^{12} cm^{-2}, respectively.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1109-1113
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Precession of Quasi-Bound States in Heterostructures with Spin-Orbit Interaction
Autorzy:
Isić, G.
Indjin, D.
Ikonić, Z.
Milanović, V.
Radovanović, J.
Harrison, P.
Powiązania:
https://bibliotekanauki.pl/articles/1791209.pdf
Data publikacji:
2009-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
73.20.At
73.21.Fg
Opis:
We use a finite-difference model that is capable of describing the single state spin dynamics in a double-barrier AlGaAs heterostructure. The use of Green's functions enables a description of the double-barrier structure by a finite matrix while the interaction with contacts is described by appropriate self-energies. To account for interface roughness scattering, a self-energy $Σp_{IR}$(E, k) is derived within the random phase approximation. The dominant part is due to in-plane momentum relaxation while a smaller part describing spin-flip scattering is neglected. The former only decreases the state lifetime while the latter can also affect the spin precession frequency.
Źródło:
Acta Physica Polonica A; 2009, 116, 4; 513-515
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiband d-p Model for the Description of Sr₂RuO₄
Autorzy:
Rościszewski, K.
Oleś, A.
Powiązania:
https://bibliotekanauki.pl/articles/1385178.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.25.Dk
75.47.Lx
71.70.Ej
Opis:
We study electronic structure of multiband d-p model describing RuO₄ layer such as realized in Sr₂RuO₄. The model takes into account nearest-neighbor anisotropic ruthenium-oxygen and oxygen-oxygen hoppings, intra-atomic Coulomb interaction, Hund's exchange and in addition spin-orbit coupling on ruthenium. The RuO₄ is universally considered as a pure $t_{2g}$ system (with $e_{g}$ orbitals empty) due to sizable gap between $t_{2g}$ and $e_{g}$ levels. We show that ruthenium $e_{g}$ orbitals are in fact occupied, similarly like showed earlier for CoO₂ layers.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 260-262
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three localized f electrons in UPd₂Al₃ and in UGe₂ intermetallics
Autorzy:
Radwanski, R.
Nalecz, D.
Ropka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1062036.pdf
Data publikacji:
2016-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
75.10.Dg
75.30.Gw
Opis:
We have calculated the strength of the excitations between the crystal-field states which are in agreement with inelastic-neutron-scattering results. This agreement confirms the existence in the heavy-fermion superconductor UPd₂Al₃ the crystal-field electronic structure being the finger-print of the U^{3+} ions with three localized f electrons forming strongly-correlated atomic-like quantum system 5f³. The ionic integrity and the low-energy crystal-field electronic structure is preserved in this metallic system in the meV scale as has been postulated in the Quantum Atomistic Solid State theory (QUASST). We provide preliminary results with the U^{3+} ion in UGe₂ showing the ground-state eigenfunction which reproduces the ordered magnetic-moment value of 1.48 μ_{B}. This moment is composed from the dominant orbital contribution (2.6 μ_{B}) and the opposite spin moment (1.12 μ_{B}).
Źródło:
Acta Physica Polonica A; 2016, 130, 2; 545-550
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Doping Dependence of Spin Dynamics of Drifting Electrons in GaAs Bulks
Autorzy:
Spezia, S.
Persano Adorno, D.
Pizzolato, N.
Spagnolo, B.
Powiązania:
https://bibliotekanauki.pl/articles/1506224.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
72.25.Dc
72.25.Rb
Opis:
We study the effect of the impurity density on lifetimes and relaxation lengths of electron spins in the presence of a static electric field in an n-type GaAs bulk. The transport of electrons and the spin dynamics are simulated by using a semiclassical Monte Carlo approach, which takes into account the intravalley scattering mechanisms of warm electrons in the semiconductor material. Spin relaxation is considered through the D'yakonov-Perel mechanism, which is the dominant mechanism in III-V semiconductors. The evolution of spin polarization is analyzed by computing lifetimes and depolarization lengths as a function of the doping density in the range $10^{13}$ ÷ 5 × $10^{16} cm^{-3}$, for different values of the amplitude of the static electric field (0.1 ÷ 1.0 kV/cm). We find an increase of the electron spin lifetime as a function of the doping density, more evident for lattice temperatures lower than 150 K. Moreover, at very low intensities of the driving field, the spin depolarization length shows a nonmonotonic behaviour with the density. At the room temperature, spin lifetimes and depolarization lengths are nearly independent on the doping density. The underlying physics is analyzed.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 250-252
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Infrared Spectroscopy of GaAs Doped with Mn
Autorzy:
Rutkowska, A.
Wasik, D.
Witowski, A.
Sadowski, M.
Orłowski, W.
Strzelecka, G.
Hruban, A.
Kamińska, M.
Twardowski, A.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2044531.pdf
Data publikacji:
2005-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
78.20.Ls
78.30.Fs
Opis:
We found that the fine structure related to Lyman spectra of [Mn$\text{}^{2+}$(d$\text{}^{5}$) + a hole] centers in GaAs was present only for samples with low Mn concentration. Such samples, at low temperature, did not show any hopping conductance within Mn impurity band. Magnetooptical measurements revealed that magnetic field induced splitting of the Lyman optical transitions was larger than Zeeman splitting observed for typical shallow acceptors in GaAs, like Be, Zn, and C. This experimental result proved that in the case of Mn acceptor impurity, the exchange coupling of a hole and the S = 5/2 Mn$\text{}^{2+}$(d$\text{}^{5}$) core could not be neglected, which was in accordance with the [Mn$\text{}^{2+}$(d$\text{}^{5}$) + a hole] model of the neutral Mn center in GaAs.
Źródło:
Acta Physica Polonica A; 2005, 108, 5; 845-849
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of Very Small Zeeman Splittings in GaN:Mn,Mg by Faraday Rotation
Autorzy:
Wołoś, A.
Kossacki, P.
Golnik, A.
Kamińska, M.
Gaj, J. A.
Twardowski, A.
Grzegory, I.
Boćkowski, M.
Porowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2035615.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.20.Ls
71.70.Ej
71.55.Eq
71.20.Nr
Opis:
In this work we demonstrate an application of Faraday rotation for measuring an extremely small Zeeman splitting of an Mn related absorption line placed at 1.417 eV in optical absorption spectrum of Mn and Mg doped gallium nitride. Analysis of the collected spectra allowed us to determine the value of the splitting as equal to 0.12±0.01 meV at 6 T. This data should help in establishing the nature of the observed absorption band.
Źródło:
Acta Physica Polonica A; 2002, 102, 4-5; 695-699
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Orbit Interaction in a Spherical Quantum Dot
Autorzy:
Mikhail, I.
Ismail, I.
El Shafee, M.
Powiązania:
https://bibliotekanauki.pl/articles/1198659.pdf
Data publikacji:
2014-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.-i
71.70.Ej
73.21.La
75.70.Tj
Opis:
The conventional spin-orbit interaction due to the presence of an off-center impurity located in a spherical quantum dot of finite confining potential has been investigated. The different effective masses of dot and barrier are taken into consideration. The spin-orbit interaction has been calculated in the excited state (2p). The variational method has been applied by using a new form of the trial wave function in addition to the conventional form that has been used in previous work. The new form has the advantage of satisfying the boundary conditions at the interface between dot and barrier in the case of different masses. It has been shown that the spin-orbit interaction takes its highest value when the impurity is located in the vicinity of the position at which the radial electron probability takes its maximum value. The corresponding results of a central impurity has been investigated as the limiting case when the impurity radial coordinate tends to zero. The case of central impurity has been further explored by using the exact solution in the state (2p) of the radial Schrödinger equation in the presence of the impurity.
Źródło:
Acta Physica Polonica A; 2014, 125, 5; 1197-1205
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charged Excitons in the Quantum Hall Regime
Autorzy:
Schüller, C.
Broocks, K.-B.
Schröter, P.
Heyn, C.
Heitmann, D.
Bichler, M.
Wegscheider, W.
Apalkov, V. M.
Chakraborty, T.
Powiązania:
https://bibliotekanauki.pl/articles/2038336.pdf
Data publikacji:
2004-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.-y
71.30.+h
71.35.Ji
71.70.Ej
Opis:
We review our recent optical experiments on two-dimensional electron systems at temperatures below 1 K and under high magnetic fields. The two-dimensional electron systems are realized in modulation-doped GaAs-AlGaAs single quantum wells. Via gate electrodes the carrier density of the two-dimensional electron systems can be tuned in a quite broad range between about 1×10$\text{}^{10}$ cm$\text{}^{-2}$ and 2×10$\text{}^{11}$ cm$\text{}^{-2}$. In dilute two-dimensional electron systems, at very low electron densities, we observe the formation of negatively charged excitons in photoluminescence experiments. In this contribution we report about the observation of a dark triplet exciton, which is observable at temperatures below 1 K and for electron filling factors <1/3, i.e., in the fractional quantum Hall regime only. In experiments where we have increased the density of the two-dimensional electron systems so that a uniform two-dimensional electron system starts to form, we have found a strong energy anomaly of the charged excitons in the vicinity of filling factor 1/3. This anomaly was found to exist in a very narrow parameter range of the density and temperature, only. We propose a model where we assume that localized charged excitons and a uniform Laughlin liquid coexist. The localized charged exciton in close proximity to the Laughlin liquid leads to the creation of a fractionally-charged quasihole in the liquid, which can account for the experimentally observed anomaly.
Źródło:
Acta Physica Polonica A; 2004, 106, 3; 341-353
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resonant Spin Splitting in III-V Semiconductors
Autorzy:
Skierkowski, A.
Majewski, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/2044536.pdf
Data publikacji:
2005-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.Ar
71.70.Ej
71.20.-b
71.20.Nr
Opis:
We present first-principles studies of the zero field spin splitting of energy bands in typical III-V semiconductors. Our calculations reveal that the strain induces linear-k spin splitting of the conduction band in theΓ point, which is linear in strain, and determine the magnitude of the so-called acoustic phonon constant that characterizes the magnitude of the spin splitting. In addition, we show that optical phonons lead to spin-flip processes and we present quantitative results for the spin-phonon deformation potentials in GaAs. Most importantly, the calculations show that the linear-k spin splitting can be resonantly enhanced when bands cross in a particular point of the Brillouin zone. This resonant enhancement of the bulk inversion asymmetry coupling constant by more than one order of magnitude was observed in both valence and conduction bands and can be steered by the application of the external stress. This allows tailoring of the spin relaxation and spin precession of conduction electrons in nanostructures to a much larger extent than was hitherto assumed.
Źródło:
Acta Physica Polonica A; 2005, 108, 5; 867-872
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Jahn-Teller Effect on Magnetic Properties of Fe-Based Semimagnetic Semiconductors
Autorzy:
Lebeckl, K.
Twardowski, A.
Liro, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1887005.pdf
Data publikacji:
1991-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.90.+w
71.70.Ej
71.70.Ch
75.50.Pρ
Opis:
We report results of calculations of magnetic properties (specific heat, magnetization) of Fe-based Semimagnetic Semiconductors including Jahn-Teller coupling between Fe electronic states and phonons.
Źródło:
Acta Physica Polonica A; 1991, 79, 2-3; 373-375
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction of the adiabatic potential of a symmetric molecule in the vicinity of charged semiconductor surface
Autorzy:
Bercha, S.
Glukhov, K.
Kharkhalis, L.
Sznajder, M.
Powiązania:
https://bibliotekanauki.pl/articles/1157162.pdf
Data publikacji:
2016-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.-b
71.70.Ej
61.50.Ah
02.20.-a
Opis:
We present a description of the symmetry-based method for the construction of the adiabatic potential of a symmetric molecule near the charged semiconductor surface. For this purpose, a transformation of the adiabatic potential of a free high symmetric molecule (D_{3d}) in the presence of uniform electric field is investigated. The obtained adiabatic potential is analyzed with respect to the stability of molecule in the vicinity of charged surface, as a dependence of its orientation in the electric field.
Źródło:
Acta Physica Polonica A; 2016, 129, 1a; A-120-A-122
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-Reversal Invariant Topological Superconductivity in Quasi-One-Dimensional Structures
Autorzy:
Mammadova, S.
Nakhmedov, E.
Alekperov, O.
Powiązania:
https://bibliotekanauki.pl/articles/1398788.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.78.-w
71.10.Pm
71.70.Ej
74.50.+r
Opis:
It is shown that a time-reversal invariant topological superconductivity can be realized in a quasi-one-dimensional structure, which is fabricated by filling the superconducting materials into the periodic channel of dielectric matrices like zeolite and asbestos under high pressure. The topological superconducting phase sets up in the presence of large spin-orbit interactions when s-wave intra-wire and d-wave inter-wire pairings take place. Kramers pairs of Majorana bound states emerge at the edges of each wire. The time-reversal topological superconductor belongs to DIII class of symmetry with a Z₂ invariant.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 800-802
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ferromagnetic Resonance Studies of La$\text{}_{0.67}$Ca$\text{}_{0.33}$MnO$\text{}_{3}$ Film under Stress
Autorzy:
Kundys, B.
Dyakonov, V. P.
Baran, M.
Gierłowski, P.
Szymczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/2037113.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Jt
75.80.+q
68.60.Bs
71.70.Ej
Opis:
Ferromagnetic resonance spectra of the La$\text{}_{0.67}$Ca$\text{}_{0.33}$MnO$\text{}_{3}$ ferromagnetic film deposited onto the x-cut LiNbO$\text{}_{3}$ substrate were investigated in a wide temperature range. The strain was mechanically introduced into the film using a special holder configuration. This leads to a shift of resonance field with respect to that of the as-grown sample. Analysis of the magnetic resonance shift, induced by a mechanical stress, allowed us to determine the magnetostriction constant λ$\text{}_{100}$. The magnetostriction determined in this way versus saturation magnetization could be well described by the Callen and Callen theory suggesting the domination of the single ion crystal field interaction in the sample being in the ferromagnetic state.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 133-139
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oblique Reflection of Electrons from a Potential Barrier in Heterostructures
Autorzy:
Pfeffer, P.
Zawadzki, W.
Powiązania:
https://bibliotekanauki.pl/articles/1205321.pdf
Data publikacji:
2014-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ej
73.22.Dj
73.40.-c
75.76.+j
Opis:
Reflection of electrons from a potential barrier in heterostructures is described. An electric field of the barrier causes spin splitting of electron energies via the spin-orbit interaction and its form is calculated in the three-level $k·p$ model for a nontrivial case of unbound electrons. It is shown that if the potential barrier is the only source of the spin-orbit interaction, the spin-flip electron reflections are not possible. However, there appear two unexpected possibilities related to the spin-orbit interaction: (a) non-attenuated electron propagation in the barrier whose height exceeds the energies of incoming electrons, (b) total reflection of electrons whose energies exceed barrier's height. It is indicated that the system can serve as a source of spin-polarized electron beams.
Źródło:
Acta Physica Polonica A; 2014, 126, 3; 820-826
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal Structure and Chemical Characterization of $La_{0.7}Sr_{0.3}Mn_{0.7}Ti_{0.3-x}Al_{x}O_3$ (0 ≤ x ≤ 0.15) Compounds
Autorzy:
Troyanchuk, I.
Bushinsky, M.
Tereshko, N.
Fedotova, V.
Partyka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1398340.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.fm
68.37.Hk
71.70.Ej
75.30.Et
Opis:
Neutron powder diffraction and magnetization measurements have been performed for $La_{0.7}Sr_{0.3}Mn_{0.7}Ti_{0.3-x}Al_xO_3$ (0 ≤ x ≤ 0.15) stoichiometric compounds. Increase of the Al³⁺ content enlarges the Mn⁴⁺ ions fraction from 0% (x=0) up to around 20% (x=0.15). The x=0 composition around 150 K exhibits a structural transition from the rhombohedral phase to the orthorhombic one whereas the crystal structure of the compounds with x=0.1 and 0.15 remains to be rhombohedral down to 2 K. The substitution of Ti⁴⁺ by Al³⁺ ions is accompanied by a gradual increase in the bond angle Mn-O-Mn and decrease in the Mn-O bond length which lead to enhancement of the covalent component of the chemical bond. All these compounds exhibit ferromagnetic components below 100 K. Magnetic moments estimated per manganese from the neutron powder diffraction data are found to be around $1.3 μ_{B}$ (x=0) and $1.7 μ_{B}$ (x=0.1 and 0.15) at 2 K. It is suggested that ferromagnetism is originated predominantly from the Mn³⁺-O-Mn³⁺ and Mn³⁺-O-Mn⁴⁺ superexchange interactions whereas bond angles fluctuation leads to magnetic frustrations. Enhancement of covalence slightly increases ferromagnetism.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 240-244
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Double Reflection of Electron Spin in Semiconductors
Autorzy:
Dargys, A.
Powiązania:
https://bibliotekanauki.pl/articles/1505522.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
72.25.Dc
71.70.Ej
03.65.Fd
Opis:
Reflection of spin-polarized electron from a potential barrier in bulk semiconductor in the presence of spin-orbit interaction is considered. The spin-orbit interaction brings about double electron reflection at oblique incidence of electronic beam onto the barrier. The competition between the Rashba and Dresselhaus spin-orbit mechanisms during double reflection is discussed. The problem was solved within the Clifford algebra framework, which allows one to describe the spin in a real Euclidean $ℰ_3$ space rather than in an abstract Hilbert space.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 161-163
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoresistance and Electroluminescence near the Curie-Weiss Temperature in the $Zn_{1-x}Mn_{x}Te$ Light Emitting Devices
Autorzy:
Van Khoi, Le
Avdonin, A.
Szymczak, R.
Gałązka, R.
Potemski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1791358.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Gm
71.70.Ej
75.50.Pp
78.20.Ls
78.60.Fi
Opis:
The light emitting devices based on the $p-Zn_{1-x}Mn_{x}Te$ bicrystals have been fabricated. The $Zn_{1-x}Mn_{x}Te$ devices produce red and green emission originating from the internal d-shell transitions in the $Mn^{2+}$ ions and the donor-acceptor pairs recombination, respectively. A critical behavior of the magnetic field dependence of the green emission intensity and a positive magnetoresistance near the Curie-Weiss temperature in the $Zn_{1-x}Mn_{x}Te$ devices was observed.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 941-943
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Edelstein Effect in the Presence of Impurity Spin-Orbit Scattering
Autorzy:
Maleki Sheikhabadi, A.
Raimondi, R.
Shen, Ka
Powiązania:
https://bibliotekanauki.pl/articles/1032406.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.-b
71.70.Ej
72.20.Dp
85.75.-d
Opis:
In this paper we study the current-induced spin polarization in a two-dimensional electron gas, known also as the Edelstein effect. Compared to previous treatments, we consider both the Rashba and Dresselhaus spin-orbit interaction as well as the spin-orbit interaction from impurity scattering. In evaluating the Kubo formula for the spin polarization response to an applied electric field, we explicitly take into account the side-jump and skew-scattering effects. We show that the inclusion of side-jump and skew-scattering modifies the expression of the current-induced spin polarization.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 135-139
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Emission and Vibronic Transitions in Uranium(3+) Doped Cs$\text{}_{2}$LiYCl$\text{}_{6}$ Single Crystals
Autorzy:
Karbowiak, M.
Simoni, E.
Drożdżyński, J.
Hubert, S.
Powiązania:
https://bibliotekanauki.pl/articles/1945642.pdf
Data publikacji:
1996-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
33.50.Dq
33.55.Be
71.70.Ej
81.10.Fq
Opis:
Uranium(3+) doped single crystals of Cs$\text{}_{2}$LiYCl$\text{}_{6}$ with a 0.3 and 2.0% U$\text{}^{3+}$ concentration have been obtained by the Bridgman-Stockbarger method. Luminescence spectra of the crystals were recorded at 27 and 15 K, respectively. The emission bands observed in the visible and near infrared regions have been assigned to transitions from the $\text{}^{4}$I$\text{}_{11}\text{}_{/}\text{}_{2}$ , $\text{}^{4}$F$\text{}_{3}\text{}_{/}\text{}_{2}$ , and $\text{}^{4}$G$\text{}_{7}\text{}_{/}\text{}_{2}$ levels to the $\text{}^{4}$I$\text{}_{9}\text{}_{/}\text{}_{2}$ ground level.
Źródło:
Acta Physica Polonica A; 1996, 90, 2; 367-370
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Layered Cobaltites: Synthesis, Oxygen Nonstoichiometry, Transport and Magnetic Properties
Autorzy:
Conder, K.
Podlesnyak, A.
Pomjakushina, E.
Stingaciu, M.
Powiązania:
https://bibliotekanauki.pl/articles/2047176.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.80.Ga
71.27.+a
75.47.De
61.12.Ld
71.70.Ej
Opis:
Complex cobalt oxide perovskite-derived compounds with a general formula LnBaCo$\text{}_{2}$O$\text{}_{5+x}$ (Ln = rare earth) attracted considerable interests because of their interesting properties: magnetic and metal-insulator transitions, giant magnetoresistance, ionic conductivity, and a structural similarity to high temperature superconductors. All the compounds are oxygen non-stoichiometric (0
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 7-14
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Luminescence and Excitation Spectra of U$\text{}^{3+}$ doped RbY$\text{}_{2}$Cl$\text{}_{7}$ Single Crystals
Autorzy:
Karbowiak, M.
Murdoch, K.
Drożdżyński, J.
Edelstein, N.
Hubert, S.
Powiązania:
https://bibliotekanauki.pl/articles/1945646.pdf
Data publikacji:
1996-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
33.50.I3q
33.55.Be
71.70.Ej
81.10.Fq
Opis:
Uranium(3+) doped single crystals of RbY$\text{}_{2}$Cl$\text{}_{7}$ with a uranium concentration of 0.05% and 0.2% were grown by the Bridgman-Stockbarger method using RbU$\text{}_{2}$Cl$\text{}_{7}$ as the doping substance. Polished plates of ca. 5 mm in diameter were used for measurements of luminescence and excitation spectra. Since the U$\text{}^{3+}$ ions occupy two somewhat different site symmetries, a splitting of all observed f-f bands was observed. The analysis of the spectra enabled definitively an assignment of 22 crystal field bands for both site symmetries as well as the total crystal field splitting of the ground level, equal to 473 cm$\text{}^{-1}$ and 567 cm$\text{}^{-1}$ for the first and second site symmetry, respectively.
Źródło:
Acta Physica Polonica A; 1996, 90, 2; 371-376
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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