Abstract
We show that spin Heisenberg spin chains with an additional three-body interaction of the form possess fully dimerized ground states if the ratio of the three-body interaction to the bilinear one is equal to . This result generalizes the Majumdar-Ghosh point of the chain, to which the present model reduces for . For , we use the density matrix renormalization group method to show that the transition between the Haldane and the dimerized phases is continuous with a central charge . Finally, we show that such a three-body interaction appears naturally in a strong-coupling expansion of the Hubbard model, and we discuss the consequences for the dimerization of actual antiferromagnetic chains.
- Received 15 October 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.127202
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