2004/06/30 by Johannes Richter, J. Richter, J. Schulenburg +2 · 2 citations
Earth and Planetary Sciences · Physics and Astronomy · #Advanced Condensed Matter Physics #High-pressure geophysics and materials #Physics of Superconductivity and Magnetism #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.70.174454
published as Phys. Rev. B 70, 174454 (2004) · new extended version (6 pages, 6 figures) as published in Physical Review B
openalex publication_date 2004/11/29 · arxiv created 2004/12/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 kagom'e 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 lattice exhibits a huge nontrivial degeneracy like on the kagom'e 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.