We numerically study the spin-1/2 antiferromagnetic Heisenberg model on the kagom\'{e} lattice using the density-matrix renormalization group (DMRG) method. We find that the ground state is a magnetically disordered spin liquid, characterized by an exponential decay of spin-spin correlation function in real space and a magnetic structure factor showing system-size independent peaks at commersurate antiferromangetic wavevectors. We obtain a spin triplet excitation gap ΔE(S=1)=0.055±0.005 by extrapolation based on the large size results, and confirm the presence of gapless singlet excitations. The physical nature of such an exotic spin liquid is also discussed.
@article{arxiv.0804.1616,
title = {DMRG Numerical Study of the Kagom\'{e} Antiferromagnet},
author = {H. C. Jiang and Z. Y. Weng and D. N. Sheng},
journal= {arXiv preprint arXiv:0804.1616},
year = {2008}
}