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Phase Diagram of the Heisenberg Spin Ladder with Ring Exchange

V. Gritsev·B. Normand·D. Baeriswyl
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Abstract

We investigate the phase diagram of a generalized spin-1/2 quantum antiferromagnet on a ladder with rung, leg, diagonal, and ring-exchange interactions. We consider the exactly soluble models associated with the problem, obtain the exact ground states which exist for certain parameter regimes, and apply a variety of perturbative techniques in the regime of strong ring-exchange coupling. By combining these approaches with considerations related to the discrete Z_4 symmetry of the model, we present the complete phase diagram.

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V. Gritsev, B. Normand, D. Baeriswyl. 2004-05-14. Phase Diagram of the Heisenberg Spin Ladder with Ring Exchange. https://doi.org/10.1103/physrevb.69.094431

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