Double Semion Phase in an Exactly Solvable Quantum Dimer Model on the Kagome Lattice

TL;DR

This paper introduces an exactly solvable quantum dimer model on the kagome lattice that stabilizes the double semion topological order, expanding understanding of exotic quantum phases in frustrated magnetic systems.

Contribution

It presents a new exactly solvable quantum dimer model on the kagome lattice that realizes the double semion topological order, along with a microscopic spin Hamiltonian that captures its low-energy physics.

Findings

The model stabilizes the double semion phase over a wide parameter range.

Exact diagonalization confirms the phase's stability.

A microscopic spin Hamiltonian is proposed for experimental relevance.

Abstract

Quantum dimer models typically arise in various low energy theories like those of frustrated antiferromagnets. We introduce a quantum dimer model on the kagome lattice which stabilizes an alternative $\mathbb{Z}_2$ topological order, namely the so-called "double semion" order. For a particular set of parameters, the model is exactly solvable, allowing us to access the ground state as well as the excited states. We show that the double semion phase is stable over a wide range of parameters using numerical exact diagonalization. Furthermore, we propose a simple microscopic spin Hamiltonian for which the low-energy physics is described by the derived quantum dimer model.