Test of Universality in Anisotropic 3D Ising Model

Chen and Dohm predicted theoretically in 2004 that the widely believed universality principle is violated in the Ising model on the simple cubic lattice with more than only six nearest neighbours. Schulte and Drope by Monte Carlo simulations found such violation, but not in the predicted direction. Selke and Shchur tested the square lattice. Here we check only this universality for the susceptibility ratio near the critical point. For this purpose we study first the standard Ising model on a simple cubic lattice with six nearest neighbours, then with six nearest and twelve next-nearest neighbours, and compare the results with the Chen-Dohm lattice of six nearest neighbours and only half of the twelve next-nearest neighbours. We do not confirm the violation of universality found by Schulte and Drope in the susceptibility ratio.Comment: 6 pages including 4 figures, Physica A, in pres

Characteristics of electomagnetic and magneto-static surface waves in metal-dielectric-ferrite-left handed waveguide layered structure

Some works have been carried out on studying metamaterials with negative electrical permittivity and negative magnetic permeability which called Left-handed materials (LHM), the propagation dispersion characteristics of magnetic waves in waveguide structures containing LHM. In this communication, we investigate the dispersion characteristics of magnetic surface waves in a metal-dielectric-ferrite (YIG)-LHM layered waveguide structure. Several characteristics of the propagation are also obtained especially on the non-reciprocal behavior. It has been noticed that the non-reciprocal behavior of the wave propagation has been obtained in the forward direction for the electromagnetic waves whereas this reciprocal behavior has been found in the forward and backward directions for the magneto-static surface waves. It should be stressed that the addition of the LHM layer to the above waveguide structure has been noticed to dominate the control of the direction of the dispersion curves from forward to backward wave propagation