arXiv:cond-mat/0501460 · Physical Review B
Effective quantum dimer model for trimerized kagomé antiferromagnet
Mike E. Zhitomirsky
Abstract
An effective spin-orbit Hamiltonian is derived for a spin-$1∕2$ trimerized kagom\'e 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. The characteristic energy scale for the dimer model constitutes only a small fraction of the weaker exchange coupling constant.