arXiv:1612.06899 · Physical review. B./Physical review. B
Resonating valence bond states with trimer motifs
Hyun‐Yong Lee, Yun-Tak Oh, Jung Hoon Han, Hosho Katsura
Abstract
A trimer resonating valence bond (tRVB) state consisting of an equal-weight superposition of trimer coverings on a square lattice is proposed. A model Hamiltonian of the Rokhsar-Kivelson type for which the tRVB becomes the exact ground state is written. The state is shown to have ${9}^{g}$ topological degeneracy on a genus $g$ surface and support ${\mathbb{Z}}_{3}$ vortex excitations. Correlation functions show exponential behavior with a very short correlation length consistent with the gapped spectrum. The classical problem of the degeneracy of trimer configurations is investigated by the transfer matrix method.