Lieb-Schultz-Mattis constraint, symmetries, excitation and anomaly of the quantum spin ice models in the planar pyrochlore lattice (2306.02522v1)

Abstract: We consider the quantum spin ice models in the planar pyrochlore lattice. The models are obtained by perturbing the Ising model with different lattice symmetry preserving quantum fluctuations. We map these models to a compact U(1) lattice gauge theory and discuss its global symmetries which include the 1-form U(1) global symmetry. Utilizing the higher form generalization of the Lieb-Schultz-Mattis theorem and also the monopole effect in the compact lattice gauge theory, we show that these models have "persistent" translation symmetry breaking valence bond solid phase around the Ising limit even the perturbation explicitly breaks all the spin rotation symmetry. We find the excitation in this phase can be described by an abelian Higgs model with charge $\pm2$ monopoles, this model is recently found to have a mixed 't Hooft anomaly. The one of the consequences of this anomaly is the domain wall in this phase may support deconfined excitations on it, we explicitly construct a solvable domain wall carries such anomaly. The spectrum of the excitations is also studied, we find the spectral weight of the spectrum in the low energy sector along the high symmetry momentum paths is strongly restricted by the 1-form global symmetries. Specially, we show the spectrum directly measures on the domain wall along $q_{2}=\pm q_1$ momentum paths.