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Renormalization group and nonlinear susceptibilities of cubic ferromagnets at criticality

D. V. Pakhnin·A. I. Sokolov
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Abstract

For the three-dimensional cubic model, the nonlinear susceptibilities of the fourth, sixth, and eighth orders are analyzed and the parameters δ^(i) characterizing their reduced anisotropy are evaluated at the cubic fixed point. In the course of this study, the renormalized sextic coupling constants entering the small-field equation of state are calculated in the four-loop approximation and the universal values of these couplings are estimated by means of the Pade-Borel-Leroy resummation of the series obtained. The anisotropy parameters are found to be: δ^(4) = 0.054 +/- 0.012, δ^(6) = 0.102 +/- 0.02, and δ^(8) = 0.144 +/- 0.04, indicating that the anisotropic (cubic) critical behavior predicted by the advanced higher-order renormalization-group analysis should be, in principle, visible in physical and computer experiments.

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D. V. Pakhnin, A. I. Sokolov. 2001-09-17. Renormalization group and nonlinear susceptibilities of cubic ferromagnets at criticality. https://doi.org/10.1103/physrevb.64.094407

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