Numerical studies of antiferromagnetism on a Kagomé net

We investigate the Heisenberg antiferromagnet with spins on a Kagomé net as recently proposed to explain an anomaly in the heat capacity of adsorbed ${}_{}{}^3{}_{}{}^{}\mathrm{He}$. The model reveals a disordered ground state from our spin-wave calculation which is consistent with the results of the spin-spin correlation functions computed by direct diagonalization of small clusters. We also obtain evidence of a double-peak feature in the heat capacity using the decoupled-cell Monte Carlo simulation technique introduced by Homma et al.