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Unified phase diagram of models exhibiting neutral-ionic transition

Ö. Legeza·K. Buchta·J. Sólyom
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Abstract

We have studied the neutral-ionic transition in organic mixed-stack compounds. A unified model has been derived which, in limiting cases, is equivalent to the models proposed earlier, the donor-acceptor model and the ionic Hubbard model. Detailed numerical calculations have been performed on this unified model with the help of the density-matrix renormalization-group (DMRG) procedure calculating excitation gaps, ionicity, lattice site entropy, two-site entropy, and the dimer order parameter on long chains and the unified phase diagram has been determined.

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Ö. Legeza, K. Buchta, J. Sólyom. 2005-11-03. Unified phase diagram of models exhibiting neutral-ionic transition. https://doi.org/10.1103/physrevb.73.165124

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