Classical vertex model dualities in a family of 2D frustrated quantum antiferromagnets

TL;DR

This paper explores dualities between classical vertex models and quantum antiferromagnets, revealing critical points and topological phases through exact mappings and numerical analysis.

Contribution

It introduces a framework connecting quantum dimer models to classical vertex models, identifying self-dual points as critical and constructing Hamiltonians with topological order.

Findings

Self-dual vertex models are critical at the RK point.

Numerical evidence suggests no phase transition in non-bipartite cases.

Constructed Hamiltonians host $\ ext{Z}_2$ topological phases.

Abstract

We study a general class of easy-axis spin models on a lattice of corner sharing even-sided polygons with all-to-all interactions within a plaquette. The low energy description corresponds to a quantum dimer model on a dual lattice of even coordination number with a multi dimer constraint. At an appropriately constructed frustration-free Rokhsar-Kivelson (RK) point, the ground state wavefunction can be exactly mapped onto a classical vertex model on the dual lattice. When the dual lattice is bipartite, the vertex models are bonded and are self dual under Wegner's duality, with the self dual point corresponding to the RK point of the original multi-dimer model. We argue that the self dual point is a critical point based on known exact solutions to some of the vertex models. When the dual lattice is non-bipartite, the vertex model is arrowed, and we use numerical methods to argue that there is no phase transition as a function of the vertex weights. Motivated by these wavefunction dualities, we construct two other distinct families of frustration-free Hamiltonians whose ground states can be mapped onto these vertex models. Many of these RK Hamiltonians provably host $\mathbb{Z}_2$ topologically ordered phases.