J1-J2-J3 Model with Long-Range Lieb-Mattis Interaction |
| S.E. Krüger and J. Richter Institut für Theoretische Physik, Universität Magdeburg, Postfach 4120, 39016 Magdeburg, Germany |
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| Stimulated by the two-dimensional frustrated Heisenberg antiferromagnet with first-, second-, and third-neighbor couplings (J1-J2-J3 model) we consider a corresponding three-parameter model with a long-range antiferromagnetic Lieb-Mattis interaction. This model can be solved exactly and leads to a better understanding of the role of frustration in the J1-J2-J3 model. We calculate the correlations in the groundstate and consider their finite size behavior. Furthermore we present the full thermodynamic phase diagram. We find the possibility of a disordered phase at T=0. |
| DOI: 10.12693/APhysPolA.91.377 PACS numbers: 75.10.Jm |