The Ising spin model in multiple helices with hierarchically organized interactions is investigated using Monte Carlo simulations. The numerical result of specific heat shows that the Curie temperature of the ferromagnetic transition is strongly dependent on to what extent the basal helix is...

We investigated the Anderson transition in fractal-based complexes, which were generated using the dielectric-breakdown model when parameter α in the model was changed from α1 to α2 at time τ1 during the growth. When α1<α2, our nerve-cell-like complex can be considered a dendritic fractal grown on a somatic fractal. On the other hand, when α1>α2, our nebula-like complex cannot be divided into two regions. The...</α2,>

The nature of correlated electrons confined in two dimensions is analyzed using the spectral statistics of three electrons confined in a square-well quantum dot. When in a small quantum dot, the spectral statistics of electrons are similar to those of Poisson distribution. As the quantum dot...

The travelling salesman problem, in which the best route between cities to be visited is chosen from a large number of possible routes, is reconsidered using the time reversal of physical dynamics, e.g. an inverse of the diffusion process. Information mediators assigned to every city diffuse as...

A material-designing principle in which a hierarchical structure is achieved by a series of steps of folding a low-order structure into a high-order structure is introduced in comparison with periodic arrays of unit cells. Multiply looped rings are a typical example, in which a ring consists of...