Do Crossover Functions Depend on the Shape of the Interaction Profile?
Erik Luijten, Kurt Binder
Abstract
. -- We examine the crossover from classical to non-classical critical behaviour in twodimensional systems with a one-component order parameter. Since the degree of universality of the corresponding crossover functions is still subject to debate, we try to induce non-universal e#ects by adding interactions with a second length scale. Although the crossover functions clearly depend on the range of the interactions, they turn out to be remarkably robust against further variation of the interaction profile. In particular, we find that the earlier observed non-monotonic crossover of the e#ective susceptibility exponent occurs for several qualitatively di#erent shapes of this profile. Introduction. -- In recent years, there has been a revived interest in the nature of the crossover from classical to non-classical (asymptotic) critical behaviour upon approach of the critical point. This crossover between two universality classes can be observed in a great variety of many-body systems, inclu...