Physical review. B./Physical review. B
1-form symmetry and the selection rule of the plaquette valence bond solid phase on the kagome lattice
Zijian Xiong
Abstract
We study the plaquette valence bond solid phase in an XXZ-type spin-1/2 model in the kagome lattice. The low-energy theory for this phase is a U(1) lattice gauge theory on the honeycomb lattice. We find that there is an emergent 1-form U(1) symmetry at low energy and there is a mixed anomaly. We also show that this 1-form symmetry restricts the longitudinal dynamical structure factor and leads to the selection rule relating to the vanishing intensity along some high-symmetry momentum paths (e.g., the $\mathrm{\ensuremath{\Gamma}}\text{\ensuremath{-}}M$ path). Since this emergent 1-form symmetry is robust in the presence of local UV perturbation, the selection rule will also apply to the model which is obtained by perturbing the classical limit of our model.