HIGH-TEMPERATURE CRITICAL INDICES FOR CLASSICAL ANISOTROPIC HEISENBERG MODEL

被引:1
作者
JASNOW, D
WORTIS, M
机构
[1] Department of Chemistry, Cornell University, Ithaca, NY
[2] Department of Physics, University of Illinois, Urbana, IL
关键词
D O I
10.1063/1.1657624
中图分类号
O59 [应用物理学];
学科分类号
摘要
Using the vertex renormalized form of the technique developed by Englert,1 high-temperature series expansions for the spin-spin correlation function of the classical anisotropic Heisenberg model are calculated for various lattices and anisotropies through order T-8 (close-packed lattices) and T-9 (loose-packed lattices). These series are combined and then extrapolated to give the high-temperature critical indices γ (zero-field susceptibility), ν (correlation range), and α (specific heat) as functions of anisotropy. The results are consistent with the hypothesis that the critical indices only change when there is a change in the symmetry of the system, e.g., in interpolating between the Ising and isotropic Heisenberg models, indices remain Ising-like until the system becomes isotropic, at which point they appear to change discontinuously. Previous results for the limiting cases are confirmed and extended. Series for the limiting cases (spin-infinity Ising, XY and isotropic Heisenberg models) as well as for the spin-1/2 Ising model2 have been derived for the B-site spinel lattice. Analysis of these series shows that the anomalies in the critical indices, reported on the basis of six-term expansions,3 disappear with the use of longer series. © 1969 The American Institute of Physics.
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页码:1277 / &
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