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Mean-field theory of the spin-Peierls systems: Application to CuGeO3

Mohamed Azzouz·Claude bourbonnais
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Abstract

A mean-field theory of the spin Peierls systems based on the two dimensional dimerized Heisenberg model is proposed by introducing an alternating bond order parameter. Improvements with respect to previous mean-field results are found in the one-dimensional limit for the ground state and the gap energies. In two dimensions, the analysis of the competition between antiferromagnetic long range order and the spin-Peierls ordering is given as a function of the coupling constants. We show that the lowest energy gap to be observed does not have a singlet-triplet character in agreement with the low temperature thermodynamic properties of CuGeO3.

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Mohamed Azzouz, Claude bourbonnais. 1995-05-25. Mean-field theory of the spin-Peierls systems: Application to CuGeO3. https://doi.org/10.1103/physrevb.53.5090

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