Quantum characteristics of the Topological Non-connectivity Threshold (TNT), introduced in [F. Borgonovi, G.L. Celardo, M. Maianti, E. Pedersoli, J. Stat. Phys. <Emphasis Type="Bold">116, 516 (2004)], have been analyzed in the hard quantum regime. New interesting perspectives in term of the possibility to study the...</emphasis>

Persistence is studied in a financial context by mapping the time evolution of the values of the shares quoted on the London Financial Times Stock Exchange 100 index (FTSE 100) onto Ising spins. By following the time dependence of the spins, we find evidence for power law decay of the proportion...

Extensive Monte Carlo simulations are used to investigate the stability of the ferromagnetic ground state in three-dimensional systems of Ising dipoles with added quenched disorder. These systems model the collective ferromagnetic order observed in various systems with dipolar long-range...

The three-dimensional bimodal random-field Ising model is studied via a new finite temperature numerical approach. The methods of Wang-Landau sampling and broad histogram are implemented in a unified algorithm by using the N-fold version of the Wang-Landau algorithm. The simulations are...

Generalized xy lattice spin models consist of three-component unit vectors, associated with a D-dimensional lattice (say <InlineEquation ID="Equ1"> <EquationSource Format="TEX">${\mathbb{Z}}^D$</EquationSource> </InlineEquation>), parameterized by usual spherical angles (θ<Subscript>k</Subscript>,φ<Subscript>k</Subscript>), and interacting via a ferromagnetic potential restricted to nearest neighbours, of the form <InlineEquation ID="Equ2"> <EquationSource...</equationsource></inlineequation></subscript></subscript></equationsource></inlineequation>

We review, with emphasis on the dynamical point of view, the classical characteristics of the Topological Nonconnectivity Threshold (TNT), recently introduced in F. Borgonovi, G.L. Celardo, M. Maianti and E. Pedersoli, J. Stat. Phys. <Emphasis Type="Bold">116, 1435 (2004). This shows interesting connections among...</emphasis>

Dynamical topological solitons are studied in classical two-dimensional Heisenberg easy-axis ferromagnets. The properties of such solitons are treated both analytically in the continuum limit and numerically by spin dynamics simulations of the discrete system. Excitation of internal mode causes...

In this paper we study a recent generalization of the XY-model in two dimensions by using Monte Carlo method. The vortex density, specific heat, energy and critical temperature are obtained. Some results are compared with approximated analytical calculations. The nature of the phase transition...

We discuss a geometrical interpretation of the Z-invariant Ising model in terms of isoradial embeddings of planar lattices. The Z-invariant Ising model can be defined on an arbitrary planar lattice if and only if certain paths on the lattice edges do not intersect each other more than once or...

The complete phase diagrams of the antiferromagnetic spin-2 Blume-Capel Ising system is studied on the Bethe lattice by the use of exact recursion relations. In order to specify the states of the system, i.e. the different spin configurations, the ground state phase diagram is obtained on the...