Exactly solvable non-planar $\mathbb{Z}_{2}$ dimer liquids on checkerboard and ruby lattices

Abstract

We generalize an influential framework for exactly solvable quantum dimer models with dual Ising gauge theory descriptions realizing the $\mathbb{Z}_{2}$ topological phase from trivalent to tetravalent parent lattices. The resulting quantum dimer models live on crossed-medial lattices and possess the remarkable feature of having crossed plaquettes, leading to transition graphs with generically intersecting loops. This non-planar structure runs counter to established templates for analytically tractable dimer liquids. As the simplest realization of the construction, we introduce an exactly solvable quantum dimer model on the checkerboard lattice that allows an exact mapping to the toric code, thus providing a particularly direct connection between the latter and Anderson's short range resonating valence bond paradigm. We further show that a corresponding crossed ruby lattice construction, dual to an Ising gauge theory on the kagome lattice, naturally falls within the same framework. More generally, the construction gives rise to a broad class of exactly solvable crossed-medial quantum dimer models and admits natural iteration, generating cascades of solvable $\mathbb{Z}_{2}$ topological dimer liquids beyond the standard planar setting. We furthermore extend Kasteleyn methods to the relevant non-planar graphs, enabling controlled wave-function deformations away from the commuting-projector points while retaining efficient evaluation of correlation functions.