paper

Spin excitation of the Heisenberg antiferromagnet with frustration: from the bounce-lattice antiferromagnet through the maple-leaf-lattice antiferromagnet to the exact-dimer system

arXiv:2604.24055 · doi:10.1515/zna-2025-0389

Abstract

The spin-S Heisenberg antiferromagnet on the two-dimensional lattice is investigated for S=1/2 and S=1. We consider interaction at isolated dimers () and interaction bonds that form the bounce lattice (). For , the system is reduced to the maple-leaf-lattice antiferromagnet. We primarily conduct highly parallelized numerical diagonalization to examine the spin excitation gap above the ground state for various cases. For S=1/2, we report calculations for a 42-site cluster that has not been previously treated. The S=1 case is examined for the first time for clusters up to 24 sites. Regardless of whether S=1/2 or 1, we find that the system has a gapped nature for small and becomes gapless at . For S=1, we also find that another gapped region appears between the gapless case at and the boundary of the exact-dimer phase.

8 pages, 9 figures, to be published in Zeitschrift fur Naturforschung A

References in corpus (12)