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Absence of magnetic order for the spin-half Heisenberg antiferromagnet on the star lattice

J. Richter·J. Schulenburg·A. Honecker·D. Schmalfuß
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Abstract

We study the ground-state properties of the spin-half Heisenberg antiferromagnet on the two-dimensional star lattice by spin-wave theory, exact diagonalization and a variational mean-field approach. We find evidence that the star lattice is (besides the \kagome lattice) a second candidate among the 11 uniform Archimedean lattices where quantum fluctuations in combination with frustration lead to a quantum paramagnetic ground state. Although the classical ground state of the Heisenberg antiferromagnet on the star exhibits a huge non-trivial degeneracy like on the \kagome lattice, its quantum ground state is most likely dimerized with a gap to all excitations. Finally, we find several candidates for plateaux in the magnetization curve as well as a macroscopic magnetization jump to saturation due to independent localized magnon states.

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J. Richter, J. Schulenburg, A. Honecker, D. Schmalfuß. 2004-12-21. Absence of magnetic order for the spin-half Heisenberg antiferromagnet on the star lattice. https://doi.org/10.1103/physrevb.70.174454

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