Effective Quantum Dimer Model for the Kagome Heisenberg Antiferromagnet: Nearby Quantum Critical Point and Hidden Degeneracy

TL;DR

This paper develops an effective quantum dimer model for the Kagome Heisenberg antiferromagnet, revealing valence bond crystal order, hidden degeneracy, and proximity to a quantum critical point, with implications for experiments.

Contribution

It introduces a quantitative quantum dimer model capturing low-energy singlet dynamics and identifies a nearby quantum critical point and hidden degeneracy.

Findings

Valence bond crystal order with a 36-site unit cell

Hidden degeneracy between even and odd parities

Proximity to a $\\mathbb{Z}_2$ dimer liquid region

Abstract

The low-energy singlet dynamics of the Quantum Heisenberg Antiferromagnet on the Kagome lattice is described by a quantitative Quantum Dimer Model. Using advanced numerical tools, the latter is shown to exhibit Valence Bond Crystal order with a large 36-site unit cell and hidden degeneracy between even and odd parities. Evidences are given that this groundstate lies in the vicinity of a $\mathbb{Z}_2$ dimer liquid region separated by a Quantum Critical Point. Implications regarding numerical analysis and experiments are discussed.