Europhys. Lett, 47 (3), pp. 311-317 (1999)
Do crossover functions depend on the shape
of the interaction profile?
E. Luijten 1,2 and K. Binder 2
1 Max-Planck-Institut für Polymerforschung
Postfach 3148, D-55021 Mainz, Germany
2 Institut für Physik, WA 331, Johannes Gutenberg-Universität
D-55099 Mainz, Germany
(received 7 April 1999; accepted 1 June 1999)
PACS. 05.70.Jk - Critical point phenomena.
PACS. 64.60.Fr - Equilibrium properties near critical points, critical exponents.
We examine the crossover from classical to non-classical critical behaviour in two-dimensional 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 effects 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 effective susceptibility exponent occurs for several qualitatively different shapes of this profile.
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