Numerical simulations of modulated systems

Zusammenfassung

We consider numerical simulations of the two-dimensional ANNNI (anisotropic next-nearest-neighbor Ising) model compared with those of the recently analytically solved brickwork ANNNI model. Transfer-matrix and Monte Carlo calculations are shown to result in misleading results concerning the question of different phase transitions. In the Monte Carlo calculation we find freezing effects similar to those in spin-glasses.