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تسجيل مستخدم جديدGround state properties of two spin models with exactly known ground states on the square lattice
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We introduce a new two-dimensional model with diagonal four spin exchange and an exactly knownground-state. Using variational ansaetze and exact diagonalisation we calculate upper and lower bounds for the critical coupling of the model. Both for this model and for the Shastry-Sutherland model we study periodic systems up to system size 6x6.
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