Informacja

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

Wyszukujesz frazę "05.50.+q" wg kryterium: Wszystkie pola


Tytuł:
Differential Operator Technique in the Ising Spin Systems
Autorzy:
Kaneyoshi, T.
Powiązania:
https://bibliotekanauki.pl/articles/1929335.pdf
Data publikacji:
1993-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.-b
Opis:
A review is given of the differential operator technique in the Ising spin systems. The theoretical frameworks of the various models are discussed on the basis of the Ising spin identities. These can be applied to examine the magnetic properties in a variety of magnetic materials.
Źródło:
Acta Physica Polonica A; 1993, 83, 6; 703-738
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Statistical Properties of the Rough Surface
Autorzy:
Balcerzak, T.
Powiązania:
https://bibliotekanauki.pl/articles/1929299.pdf
Data publikacji:
1993-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
68.35.Md
Opis:
The temperature induced roughening of the solid surface is described by means of a discrete Gaussian model, using integral operator technique. On the basis of the exact statistical identities, the formulae for several local moments, i.e. ⟨hi⟩), ⟨(hi)$\text{}^{2}$⟩ and ⟨hihj⟩ are derived. The results of computer calculations, including surface specific heat, are presented for three lattices with z = 3, 4, and 6. In discussion, some further applications of the presented method are suggested.
Źródło:
Acta Physica Polonica A; 1993, 83, 5; 597-610
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical Behaviour of Some 2D Lattice Models
Autorzy:
Kamieniarz, G.
Blöte, H. W.J.
Dekeyser, R.
Powiązania:
https://bibliotekanauki.pl/articles/1930586.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.-i
64.60.Cn
64.60.Ak
64.60.Fr
75.40.Mg
Opis:
The density series of the non-interacting hard-square lattice gas model are reanalyzed by the ratio, Dlog Padé and differential approximant methods. The problem of poor consistency between series and other results is resolved. Transfer matrix calculations are performed, implementing both finite-size scaling and conformal invariance. Very accurate estimates of the critical exponents y$\text{}_{t}$, and y$\text{}_{h}$ are obtained in agreement with Ising universality. Furthermore, an improvement of the value of the critical density ρ$\text{}_{c}$ is found. In addition, the universal critical-point ratios of the square of the second and the fourth moment of the magnetization for ferromagnetic Ising models on the square and on the triangular lattice with periodic boundary conditions are reported.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 389-393
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effective Field Methods for Magnetic Systems
Autorzy:
Kamieniarz, G.
Dekeyser, R.
Musiał, G.
Powiązania:
https://bibliotekanauki.pl/articles/1930600.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.60.Cn
64.60.Fr
05.50.+q
75.10.Dg
75.10.Hk
75.10.Jm
75.40.Cx
75.40.Mg
Opis:
The self-consistency conditions inherent in the mean-field approximation are extended to take into account some pair correlations. Ii is shown that this extension is systematically improvable and applicable to the spin systems with short-range interactions in the entire temperature region. With two correlations included and the renormalization-group ideas implemented, the critical properties of the Ising model are satisfactorily revealed. Moreover, the improved estimates of the thermodynamical quantities for the quantum linear XY model from the finite-size calculations are found down to very low temperatures.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 413-417
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ising Model on Tangled Chain. I. Free Energy and Entropy
Autorzy:
Mejdani, R.
Powiązania:
https://bibliotekanauki.pl/articles/1931346.pdf
Data publikacji:
1994-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
65.50.+m
75.10.Hk
75.10.Nr
05.50.+q
Opis:
In this paper we have considered an Ising model defined on tangled chain, in which more bonds have been added to those of pure Ising chain. To understand their competition, particularly between ferromagnetic and antiferromagnetic bonds, we have studied, using the transfer matrix method, some simple analytical calculations and an iterative algorithm, the behaviour of the free energy and entropy, particularly in the zero-field and zero-temperature limit, for different configurations of the ferromagnetic tangled chain and different types of additional interactions (ferromagnetic or antiferromagnetic). We found that the condition J = -J' between the ferromagnetic interaction J along the chain and the antiferromagnetic interaction J' across the chain is somewhat as a "transition region" condition for this behaviour. Our results indicate also the existence of nonzero entropy at zero temperature.
Źródło:
Acta Physica Polonica A; 1994, 85, 6; 907-918
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ising Model on Tangled Chain. II. Magnetization and Susceptibility
Autorzy:
Mejdani, R.
Powiązania:
https://bibliotekanauki.pl/articles/1931347.pdf
Data publikacji:
1994-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
65.50.+m
75.10.Hk
75.10.Nr
05.50.+q
Opis:
In the preceding paper we have considered an Ising model defined on tangled chain to study the behaviour of the free energy and entropy, particularly in the zero-field and zero-temperature limit. In this paper, following the main line and basing on some results of the previous work, we shall study in the "language" of state configurations the behaviour of the magnetization and the susceptibility for different conditions of the model, to understand better the competition between the ferromagnetic bonds along the chain and the antiferromagnetic additional bonds across the chain. Particularly interesting is the behaviour of the susceptibility in the zero-field and zero-temperature limit. Exact solutions for the magnetization and susceptibility, generated by analytical calculations and iterative algorithms, are described. The additional bonds, introduced as a form of perfect disorder, indicate a particular effect on the spin correlation. We found that the condition J = -J' between the ferromagnetic interaction J along the chain and the antiferromagnetic interaction J' across the chain is somewhat as a "transition-region" condition for this behaviour.
Źródło:
Acta Physica Polonica A; 1994, 85, 6; 919-935
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulations of the 3D Ising Model at Criticality
Autorzy:
Blöte, H. W. J.
Kamieniarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1930588.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.-i
64.60.Fr
75.40.Mg
64.60.Ak
Opis:
We present some new finite-size results for the Binder cumulant that we obtained by means of a transfer-matrix perturbation expansion and by the cluster Monte Carlo methods - the Swendsen-Wang and Wolff algorithms and the largest-cluster method. A finite-size scaling analysis taking into account a correction to scaling locates the critical coupling at Kc = 0.221649(4).
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 395-398
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rarefied Band in Spectrum of Two-Magnon States of Heisenberg Ferromagnet of Clock Dial Plate
Autorzy:
Lulek, T.
Wal, A.
Powiązania:
https://bibliotekanauki.pl/articles/1933552.pdf
Data publikacji:
1995-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.30.Ds
02.20.-a
75.Jm
Opis:
The Heisenberg isotropic exchange Hamiltonian with the nearest neighbour interactions for the ring of N = 12 nodes (the clock dial plate) with the spin 1/2 has been diagonalized within the manifold of all 66 two-magnon excitations from the ferromagnetic ground state. The spectrum consists of 5 full bands, i.e. bands defined over the whole Brillouin zone, and a single band which is doubly rarefied, i.e. defined only for even values of quasimomentum. The rarefied band is found to be dispersionless outside the centre of the Brillouin zone. It separates two bands of "weakly bounded" spin waves from two other which are "weakly antibounded". The last remaining band is situated below this collection of scattered spin waves, and describes two tightly bounded spin deviations. The spectrum exhibits dispersion, but it is degenerate (singlet and quintet) at the boundary of the Brillouin zone.
Źródło:
Acta Physica Polonica A; 1995, 88, 2; 259-268
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Orientational Ordering for System of Ellipsoidal Molecules Dispersed in Cubic Lattice
Autorzy:
Mejdani, R.
Powiązania:
https://bibliotekanauki.pl/articles/1952744.pdf
Data publikacji:
1996-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.Cn
64.60.My
64.70.Md
Opis:
We represent here some results for a model of migrating and nonmigrating ellipsoidal molecules dispersed in a cubic lattice, describing: the orientational ordering in nematics, the possibility of a biaxial ordered liquid state, the orientational ordering in solid hydrogen (orto-H$\text{}_{2}$ or para-D$\text{}_{2}$) or the orientational glassy structure (the "higher rank"glass state). Through this kind of molecular ensemble (in the case of the system of ellipsoidal and spherical molecules) it is also possible to study the orientational and positional orderings in binary mixtures and to obtain the so-called plastic state.
Źródło:
Acta Physica Polonica A; 1996, 90, 6; 1127-1141
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Standard Statistical Thermodynamics with Generalized Statistical Thermodynamics Results for Ising Chain
Autorzy:
Tirnakli, U.
Demirhan, D.
Büyükkiliç, F.
Powiązania:
https://bibliotekanauki.pl/articles/1964226.pdf
Data publikacji:
1997-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
05.20.-y
Opis:
In this study, the internal energy and the specific heat of the one-dimensional Ising model obtained in the frame of the generalized statistical thermodynamics by Andrade, were somewhat extended and compared with the internal energy and the specific heat which were calculated in the standard (conventional) statistical thermodynamics. In the q → 1 case, approaching of the generalized internal energy and the specific heat to the standard well-known results, were illustrated by numerical applications. In addition to these, N ≫ 1 case was also investigated.
Źródło:
Acta Physica Polonica A; 1997, 91, 6; 1135-1042
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exchange Magnetostriction in Disordered 2D Ising Ferromagnets
Autorzy:
Kawecka-Magiera, B.
Maksymowicz, A.
Kułakowski, K.
Lenda, A.
Powiązania:
https://bibliotekanauki.pl/articles/1955466.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.80.+q
Opis:
We investigate volume and shape magnetoelastic strains of a 2D anisotropic Ising alloy with partial atomic order. Three possible origins of shape strain are distinguished: (i) anisotropy of elastic constants, (ii) anisotropy of magnetic bonds and (iii) anisotropy of the spatial derivatives of magnetic bonds. None of these mechanisms vanishes above the Curie temperature. Equilibrium strains are expressed in terms of anisotropic spin-spin nearest-neighbours correlation functions. These functions are calculated against temperature, both in ferromagnetic and paramagnetic phase. Shape strain decreases monotonously with temperature for the mechanisms (i) and (iii), and has a maximum near the Curie temperature for the case (ii). The results may be relevant for multilayer magnetic systems.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 297-301
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local Gauge and Magnetic Translation Groups
Autorzy:
Florek, W.
Powiązania:
https://bibliotekanauki.pl/articles/1964708.pdf
Data publikacji:
1997-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
11.15.Ha
05.50.+q
71.45.-d
02.20.-a
Opis:
The magnetic translation group was introduced as a set of operators T(R)=exp[-iR·(p-eA/c)/h]. However, these operators commute with the Hamiltonian for an electron in a periodic potential and a uniform magnetic field if the vector potential A (the gauge) is chosen in a symmetric way. It is showed that a local gauge field A$\text{}_{R}$(r) on a crystal lattice leads to operators, which commute with the Hamiltonian for any (global) gauge field A = A(r). Such choice of the local gauge determines a factor system ω(R,R') = T(R)T(R')T(R+R')$\text{}^{-1}$, which depends on a global gauge only. Moreover, for any potential A a commutator T(R)T(R')T(R)$\text{}^{-1}$T(R')$\text{}^{-1}$ depends only on the magnetic field and not on the gauge.
Źródło:
Acta Physica Polonica A; 1997, 92, 2; 399-402
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Study of Weak Ferromagnetism in 2D J$\text{}_{1}$-J$\text{}_{2}$ Heisenberg Model with Dzyaloshinskii-Moriya Interaction
Autorzy:
Voigt, A.
Richter, J.
Powiązania:
https://bibliotekanauki.pl/articles/1955526.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Gw
05.50.+q
75.10.Jm
Opis:
By means of exact diagonalization we consider the groundstate of the J$\text{}_{1}$-J$\text{}_{2}$ spin 1/2 Heisenberg model with an anisotropic interaction term of Dzyaloshinskii-Moriya type. We find that a Dzyaloshinskii-Moriya interaction may create a weak ferromagnetic moment. The interplay between the quantum nature of the groundstate of the pure J$\text{}_{1}$-J$\text{}_{2}$ model and the anisotropic Dzyaloshinskii-Moriya interaction favour energetically a well-defined direction of spin alignment creating anisotropic correlations.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 371-375
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics of "order-order" Relaxations in Ni$\text{}_{3}$Al Studied by Computer Simulation
Autorzy:
Oramus, P.
Kozubski, R.
Cadeville, M. C.
Pierron-Bohnes, V.
Pfeiler, W.
Powiązania:
https://bibliotekanauki.pl/articles/2011010.pdf
Data publikacji:
1999-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
05.20.Dd
66.30.-h
81.30.Hd
Opis:
The experimental investigations of "order-order" kinetics in Ni$\text{}_{3}$ Al-based L1$\text{}_{2}$-ordered intermetallic compounds revealed the relaxation curves composed of two parallel processes considerably differing in relaxation rates. A simple Ising-type model based on a vacancy mechanism of atomic jumps was used to carry the Monte Carlo simulations of long-range-order relaxations in a binary A$\text{}_{3}$B system with L1$\text{}_{2}$-type superstructure. The simulated relaxation curves fitted weighted sums of two exponentials with significantly different relaxation times. It was found out that the fast relaxation process is controlled by the dynamics of the minority B-atom jumps.
Źródło:
Acta Physica Polonica A; 1999, 96, 1; 153-160
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ground-State Energy of a Frustrated ±J Ising Model on a Strip of Squares
Autorzy:
Błaszyk, M.
Fechner, B.
Powiązania:
https://bibliotekanauki.pl/articles/2013704.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Nr
75.50.Lk
Opis:
We investigated a ±J Ising model on an infinite strip of squares of the width of one and two bonds with a random distribution of ferro- and antiferromagnetic exchange interactions. The exact ground-state energy as a function of the concentration of antiferromagnetic bonds was derived and its singular points in the complex-plane were found.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 855-858
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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