Effective quantum dimer model for trimerized kagome antiferromagnet

TL;DR

This paper derives an effective quantum dimer model for a spin-1/2 trimerized kagome antiferromagnet, revealing the dominant dimer resonances and their energy scales, which enhances understanding of low-energy singlet states.

Contribution

The study introduces a novel effective quantum dimer model for the trimerized kagome antiferromagnet, highlighting the role of short-loop resonances and small energy scales.

Findings

Quantum dimer model captures low-energy singlet states.

Dimer resonances are dominated by shortest loops.

Characteristic energy scale is a small fraction of exchange coupling.

Abstract

An effective spin-orbit Hamiltonian is derived for a spin-1/2 trimerized kagome antiferromagnet in the second-order of perturbation theory in the ratio of two coupling constants. Low-energy singlet states of the obtained model are mapped to a quantum dimer model on a triangular lattice. The quantum dimer model is dominated by dimer resonances on a few shortest loops of the triangular lattice. Characteristic energy scale for the dimer model constitutes only a small fraction of the weaker exchange coupling constant.