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1
Content available remote Formulae for Solid-on-Solid Nucleation Model
100%
Suffczyński M.
Acta Physica Polonica A
|
1991
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tom 80
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nr 5
745-750
EN
The solid-on-solid model, with nearest- and next-nearest neighbour interactions, of two-dimensional nucleation on the surface of a crystal in unstable equilibrium with its supersaturated vapour allows from the local mean direction of curved step to derive closed formulae for the shape, the area, and the activation energy for growth of the crystal nucleus. The formulae facilitate to estimate from the observed shape patterns the parameters of nucleation, to follow the evolution of the crystal nucleus with temperature and the dependence of activation energy on distance between screw dislocations which provide steps on the crystal surface.
2
Content available remote Braids for Twist Knots
100%
Suffczyński M.
Acta Physica Polonica A
|
1998
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tom 93
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nr 5-6
679-683
EN
A standardized writing of the words for braid closures of the twist knots allows one to write braid words of twist knots for general values of crossing number.
3
Content available remote Braids for Pretzel Knots
100%
Suffczyński M.
Acta Physica Polonica A
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2000
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tom 98
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nr 6
663-671
EN
The words of braid closures for the pretzel knots, in particular the twist knots relevant to molecular supercoils in biochemistry, are recorded in a standardized form, which enables one to see the regular pattern of the words, and thus to write the braid words representing pretzel knots for general values of the crossing number.
4
Content available remote Acceptor in Quantum Dot in Cubic Semiconductors
63%
Janiszewski P. , Suffczyński M.
Acta Physica Polonica A
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1995
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tom 88
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nr 6
1171-1177
EN
Energy levels and oscillator strengths for transitions between the low­est states of an acceptor in a quantum dot of finite potential barrier in cubic semiconductors have been computed in the effective-mass approxima­tion. The degeneracy of the valence band in cubic semiconductors was taken into account in the spherical approximation. Variational envelope functions consisted of a finite basis of exponentials, and had to satisfy appropriate boundary conditions to ensure the hermiticity of the Hamiltonian matrix. In typical cubic semiconductors we have found enhanced values, by an order of magnitude, of oscillator strengths for the acceptor optical transitions in the dots of radii comparable to the acceptor diameter.
5
Content available The Nonlinear Absorption Coefficient for Direct Two-Photon Creation of Biexciton
63%
Ungier W. , Suffczyński M.
Acta Physica Polonica A
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2002
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tom 101
|
nr 2
295-300
EN
The absorption coefficient for the two-photon creation of biexciton is calculated for CuCl and wurtzite crystals. Because of the resonance effect only the intermediate lowest optically active excitonic states are taken into account. The absorption coefficient is expressed by a functional of the biexciton envelope. The numerical results are computed with the envelope function of Hylleraas-Ore type (modified and minimized by Brinkman et al). The obtained results for CuCl are in good agreement with absorption measurements published by Gale and Mysyrowicz.
6
Content available remote Binding Energy of Muonium Hydride
63%
Suffczyński M. , Wolniewicz L.
Acta Physica Polonica A
|
1993
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tom 83
|
nr 2
157-159
EN
Binding energy of muonium hydride is calculated variationally with wave function dependent exponentially on three interparticle distances. The lower bound for the dissociation energy into the hydrogen atom and muonium is obtained as 3.853 eV. Expectation values of the interparticle distances are also calculated.
7
Content available remote Direct Two-Photon Creation of Excitonic Molecule in CuCl
51%
Ungier W. , Janiszewski P. , Suffczyński M.
Acta Physica Polonica A
|
2000
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tom 98
|
nr 4
411-417
EN
The probability of direct excitation of excitonic molecule in the two-photon absorption process is calculated with an Hylleraas-Ore type biexciton envelope, which is variationally optimized. In the second order of perturbation, because of the resonance effect, only the exciton Γ_{5} intermediate state is taken into account. The band structure at band extrema due to spin-orbit interaction is assumed. The transition probability of two-photon absorption is expressed by matrix element between the free exciton and the biexciton envelopes. The obtained probability of two-photon absorption in CuCl is about three orders of magnitude smaller when compared to that obtained by Hanamura.
8
Content available remote Exciton in 2D Cubic Inclusion in Hexagonal GaN
51%
Suffczyński M. , Stępniewski R. , Baranowski J.
Acta Physica Polonica A
|
1997
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tom 92
|
nr 5
993-996
EN
An inclusion of cubic GaN in an otherwise hexagonal matrix is considered to be equivalent to an effective quantum well. The exciton binding energy in a quantum well of a finite potential barrier height in the conduction and valence bands is calculated in the effective mass approximation with a variational envelope function type of Bastard and Takagahara. The exciton binding energy and the energy of exciton recombination line are computed, as a function of the well width, for realistic potential barrier heights and band-offset ratios.
9
Content available remote Excitonic Molecule in Wurtzite Crystals
51%
Ungier W. , Janiszewski P. , Suffczyński M.
Acta Physica Polonica A
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1994
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tom 85
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nr 3
607-613
EN
We calculate with the variational technique the fine structure of a biexciton in wurtzite crystals with the effective electron-hole exchange interaction taken into account. The values of the electron-hole exchange integrals are taken from the free exciton Γ_{5}-Γ_{6} splitting. We calculate the biexciton dissociation energy and the ratio of mixing of the symmetric and antisymmetric envelopes which arises from the electron-hole exchange interaction. Results are presented for CdS, CdSe and ZnS crystals.
10
Content available Size of Muonium Hydride
51%
Suffczyński M. , Kotowski T. , Wolniewicz L.
Acta Physica Polonica A
|
2002
|
tom 102
|
nr 3
351-354
EN
Binding energy and expectation values of the interparticle distances of muonium hydride are calculated variationally with a wave function dependent exponentially on three interparticle distances.
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