A COUPLED-CLUSTER TREATMENT OF SPIN-1/2 SYSTEMS WITH NEAREST-NEIGHBOR AND NEXT-NEAREST-NEIGHBOR INTERACTIONS

被引:29
|
作者
FARNELL, DJJ
PARKINSON, JB
机构
[1] Dept. of Math., Univ. of Manchester, Inst. of Sci. and Technol.
关键词
D O I
10.1088/0953-8984/6/28/024
中图分类号
O469 [凝聚态物理学];
学科分类号
070205 ;
摘要
The coupled-cluster method of quantum many-body theory is applied to 1D and 2D spin-1/2 systems with nearest-neighbour and next-nearest-neighbour isotropic exchange. Several simple approximation schemes based on a Neel model state are investigated and are found to give satisfactory results in the antiferromagnetic regime. Results are given for the ground-state energy, the order parameter and the sublattice magnetization. We obtain evidence of a phase transition.
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页码:5521 / 5532
页数:12
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