D-M Interactions and its Ground State in the Square Lattice

Authors: H. GENCER, A. BAYRI, S. EKMEKÇİ

Abstract: The Heisenberg model gives infinetely many degenerate antiferromagnetic ground state orderings [1-3]. However, this is not the case in real materials. Experimental and theoretical studies showed that there are only a few spin structures [4]. This indicate that there must be some others interactions in order to remove these high degeneraty, which are negligible compeared with the Heisenberg exchange. One of the these interaction is Dzyaloshinsky-Moriya(D-M) type exchange. We studied the D-M interactions in the square lattice and found out that it leads to a perpendicular nearest neighbours spin orderings. Considering the Heisenberg and D-M interaction togrther one can easily predict that they lead to a non-collinear spin ordering in the square lattice.

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