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arXiv · 1107.0599

Coupled-cluster calculations for the ground- and excited-states of the spin-half XXZ model

Mohammad Merdan·Y. Xian
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Abstract

The coupled-cluster method is applied to the spin-1/2 antiferromagnetic XXZ model on a square lattice by employing an approximation which contains two-body long-range correlations and high-order four-body local correlations. Improvement is found for the ground-state energy, sublattice magnetization, and the critical anisotropy when comparing with the approximation including the two-body correlations alone. We also obtain the full excitation spectrum which is in good agreement with the quantum Monte Carlo results and the high-order spin-wave theory.

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Mohammad Merdan, Y. Xian. 2012-02-21. Coupled-cluster calculations for the ground- and excited-states of the spin-half XXZ model. https://doi.org/10.1088/0953-8984%2F23%2F40%2F406001

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