Two-Dimensional Symmetrical Mixtures in an External Field of Square Symmetry

2010 ◽  
Vol 114 (1) ◽  
pp. 396-406 ◽  
Author(s):  
A. Patrykiejew ◽  
S. Sokołowski
Keyword(s):  
External Field ◽  
Two Dimensional

TWO-DIMENSIONAL WANG–LANDAU SAMPLING OF AN ASYMMETRIC ISING MODEL

2009 ◽  
Vol 20 (09) ◽  
pp. 1357-1366 ◽  
Author(s):  
SHAN-HO TSAI ◽  
FUGAO WANG ◽  
D. P. LANDAU
Keyword(s):  
Phase Diagram ◽  
Ising Model ◽  
External Field ◽  
Density Of States ◽  
Triangular Lattice ◽  
Sampling Method ◽  
Two Dimensional ◽  
Theoretical Predictions ◽  
The Spectator ◽  
Three Body

We study the critical endpoint behavior of an asymmetric Ising model with two- and three-body interactions on a triangular lattice, in the presence of an external field. We use a two-dimensional Wang–Landau sampling method to determine the density of states for this model. An accurate density of states allowed us to map out the phase diagram accurately and observe a clear divergence of the curvature of the spectator phase boundary and of the derivative of the magnetization coexistence diameter near the critical endpoint, in agreement with previous theoretical predictions.

QUANTUM QUASI-SOLITONS IN THE TWO-DIMENSIONAL FERROMAGNETIC LATTICE WITH AN EXTERNAL FIELD

2013 ◽  
Vol 27 (09) ◽  
pp. 1350058 ◽  
Author(s):  
DE-JUN LI ◽  
BING TANG ◽  
KE HU ◽  
YI TANG
Keyword(s):  
Magnetic Field ◽  
Quantum Theory ◽  
External Magnetic Field ◽  
External Field ◽  
Multiple Scale ◽  
Two Dimensional ◽  
Scale Method ◽  
Nonlinear Excitations ◽  
Localized Mode ◽  
Intrinsic Localized Mode

Based on the quantum theory and a simplified version of the multiple-scale method, the nonlinear excitations in a two-dimensional ferromagnetic lattice with an external magnetic field are analytically investigated. The standard two-dimensional nonlinear Schrödinger equation is obtained. Results show that the quantum quasi-soliton can exist in the two-dimensional ferromagnetic lattice. In addition, when the group velocity is equal to zero, at the boundary of the Brillouin zone, the quantum quasi-soliton becomes the quantum intrinsic localized mode.

Non-axisymmetric vortices in two-dimensional flows

2000 ◽  
Vol 406 ◽  
pp. 175-198 ◽  
Author(s):  
STÉPHANE LE DIZÈS
Keyword(s):  
Reynolds Number ◽  
External Field ◽  
Strain Field ◽  
Asymptotic Methods ◽  
Angular Frequency ◽  
Critical Layer ◽  
Large Reynolds Number ◽  
Two Dimensional ◽  
Axisymmetric Structures ◽  
Two Dimensional Flows

Slightly non-axisymmetric vortices are analysed by asymptotic methods in the context of incompressible large-Reynolds-number two-dimensional flows. The structure of the non-axisymmetric correction generated by an external rotating multipolar strain field to a vortex with a Gaussian vorticity profile is first studied. It is shown that when the angular frequency w of the external field is in the range of the angular velocity of the vortex, the non-axisymmetric correction exhibits a critical-point singularity which requires the introduction of viscosity or nonlinearity to be smoothed. The nature of the critical layer, which depends on the parameter h = 1/(Re ε3/2), where ε is the amplitude of the non-axisymmetric correction and Re the Reynolds number based on the circulation of the vortex, is found to govern the entire structure of the correction. Numerous properties are analysed as w and h vary for a multipolar strain field of order n = 2, 3, 4 and 5. In the second part of the paper, the problem of the existence of a non-axisymmetric correction which can survive without external field due to the presence of a nonlinear critical layer is addressed. For a family of vorticity profiles ranging from Gaussian to top-hat, such a correction is shown to exist for particular values of the angular frequency. The resulting non-axisymmetric vortices are analysed in detail and compared to recent computations by Rossi, Lingevitch & Bernoff (1997) and Dritschel (1998) of non-axisymmetric vortices. The results are also discussed in the context of electron columns where similar non-axisymmetric structures were observed (Driscoll & Fine 1990).

The Temperature of Berezinsky – Kosterlitz – Thouless Transition in Two-Dimensional Superconductor in an External Field

2014 ◽  
Vol 9 (3) ◽  
pp. 75-80
Author(s):  
Aleksandr Krinitsyn ◽  
Iliya Tikhomirov ◽  
Klimentiy Yugay
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
External Magnetic Field ◽  
External Field ◽  
Critical Field ◽  
Applied Magnetic Field ◽  
Coherence Length ◽  
Upper Critical Field ◽  
Two Dimensional ◽  
Calculated Temperature

The Method of Monte-Carlo calculated temperature of Berezinsky – Kosterlitz – Thouless transition in twodimensional superconductor 2nd type in the presence of an external magnetic field. It is shown that near the upper critical field filling cells with a size of ξ × ξ relation, where ξ – coherence length at a given temperature, corresponds to half. It is also shown that ТBKT decreases with increasing interaction between the vortices and antivortices and increase of the external applied magnetic field

Sign in / Sign up

Export Citation Format

Share Document