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Weak antiferromagnetism and dimer order in quantum systems of coupled tetrahedra

Valeri N. Kotov·Michael E. Zhitomirsky·Maged Elhajal·Frederic Mila
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Abstract

We analyze the phases of an S=1/2 spin model on a lattice of coupled tetrahedra. The presence of both Heisenberg and antisymmetric, Dzyaloshinsky-Moriya interactions can lead to two types of symmetry-broken states: non-magnetic dimer order and, unexpectedly, exotic 4 sub-lattice weak antiferromagnetic order - a state with a generically small ordered moment and non-zero chirality. External magnetic field also induces weak antiferromagnetism co-existing with strong dimer correlations in the ground state. These states are formed as a result of broken Ising symmetries and exhibit a number of unusual properties.

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Valeri N. Kotov, Michael E. Zhitomirsky, Maged Elhajal, Frederic Mila. 2004-10-28. Weak antiferromagnetism and dimer order in quantum systems of coupled tetrahedra. https://doi.org/10.1103/physrevb.70.214401

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