scholarly journals Magnetization Profile in the D= 2 Semi-Infinite Ising Model and Crossover Between Ordinary and Normal Transition

1997 ◽  
Vol 11 (17) ◽  
pp. 2075-2091 ◽  
Author(s):  
Peter Czerner ◽  
Uwe Ritschel
Keyword(s):  
Magnetic Field ◽  
Ising Model ◽  
Short Distance ◽  
Higher Dimensions ◽  
Scaling Analysis ◽  
Exact Results ◽  
Two Dimensional ◽  
Normal Transition ◽  
Surface Magnetization ◽  
Logarithmic Dependence

We study the two-dimensional semi-infinite Ising model with a free surface at or near bulk criticality. Special attention is paid to the influence of a boundary magnetic field h1 on the surface-near regime and the crossover between the fixed points at h1=0 and h1=∞. Near the surface, a smallh1 causes a steeply increasing magnetization m(z)~z3/8 log z as the distance z increases away from the surface. By means of a phenomenological scaling analysis, this phenomenon can be related to the well-known logarithmic dependence of the surface magnetization m1 on h1. Our analysis provides a deeper understanding of the existing exact results on m(z) and relates the short-distance phenomena in d=2 to those in higher dimensions. Both the results of the scaling analysis and the exact analytic profiles are corroborated by Monte Carlo simulations.

ISING MODEL IN THE MAGNETIC FIELD iπkT/2

1988 ◽  
Vol 02 (03n04) ◽  
pp. 471-481 ◽  
Author(s):  
K. Y. LIN ◽  
F. Y. WU
Keyword(s):  
Magnetic Field ◽  
Free Energy ◽  
Ising Model ◽  
Zero Field ◽  
Two Dimensional ◽  
Anisotropic Interactions ◽  
The Magnetic Field ◽  
Explicit Expressions

It is shown that the free energy and the magnetization of an Ising model in the magnetic field H = iπkT/2 can be obtained directly from corresponding expressions of these quantities in zero field, provided that the latter are known for sufficiently anisotropic interactions. Using this approach we derive explicit expressions of the free energy and the magnetization at H = iπkT/2 for a number of two-dimensional lattices.

A CORRELATION BETWEEN PERCOLATION MODEL AND ISING MODEL

1996 ◽  
Vol 07 (04) ◽  
pp. 609-612 ◽  
Author(s):  
R. HACKL ◽  
I. MORGENSTERN
Keyword(s):  
Critical Temperature ◽  
Ising Model ◽  
Percolation Threshold ◽  
Higher Dimensions ◽  
Percolation Model ◽  
Critical Values ◽  
Square Lattice ◽  
Approximation Formula ◽  
Two Dimensional

In this article we will expose a connection between critical values of percolation and Ising model, i.e., the percolation threshold pc, and the critical temperature Tc and energy Ec, respectively, by the approximation [Formula: see text]. For the two-dimensional square lattice even the identity holds. For higher dimensions — up to d = 7 — and other lattice types we find remarkably small differences from one to five percent.

Domain Analysis and Magnetic Relaxation in Thin Films

1998 ◽  
Vol 09 (06) ◽  
pp. 821-825 ◽  
Author(s):  
Tatiana G. Rappoport ◽  
F. S. de Menezes ◽  
L. C. Sampaio ◽  
M. P. Albuquerque ◽  
F. Mello
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Monte Carlo ◽  
Ising Model ◽  
Monte Carlo Simulations ◽  
Magnetic Relaxation ◽  
Film Plane ◽  
Relative Strength ◽  
Two Dimensional ◽  
Magnetic Domains

We have simulated the magnetic relaxation (M(t)) and the nucleation of magnetic domains in the presence of magnetic field in thin films with anisotropy perpendicular to the film plane. We have used Monte Carlo simulations based on the two-dimensional classical Ising model including the long-range dipole–dipole and Zeeman interactions. Domains nucleated during the magnetic relaxation exhibit very rough interfaces. We analyze the roughness and the M(t) as a function of the relative strength of dipole–dipole and Zeeman terms.

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