J. Phys. I France 7 (1997) 827-832
Energy-Energy Correlations in Square and Cubic Ising ModelsRoland R. Netz1, 2 and Ingo H. Gersonde2
1 Department of Physics, Box 351560, University of Washington, Seattle, WA 98195-1560, USA
2 Service de Physique Théorique, CEA-Saclay, 91191 Gif sur Yvette, France
(Received 9 September 1996, revised 4 February 1997, accepted 6 May 1997)
Cluster-Monte-Carlo simulations are used to calculate the structure factors associated with order-parameter and energy correlations for square and cubic Ising models, from which the corresponding correlation lengths and , respectively, are determined. The amplitude ratio is asymptotically universal but strongly influenced by the crossover from mean-field behavior. The numerically determined therefore does not reach its universal asymptotic value but agrees well with -expansion predictions including corrections to scaling. The consequences for experiments on near-critical fluids and colloidal systems are briefly discussed.
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