Ground-state properties of the S=1/2 Heisenberg antiferromagnet on a triangular lattice: a numerical study of a finite cell

Abstract
The authors study numerically a 21-site Marland-Betts type cell of the S=1/2 Heisenberg antiferromagnet on a triangular lattice with nearest-neighbour (NN) and next-nearest-neighbour (NNN) couplings. The emphasis is on a comparison of the classical picture of this model with its quantum properties. By considering the structure function S(k) they demonstrate that there is a close connection between the classical and the quantum ground states of the system. Contrary to a previous conjecture they find no significant enhancement of the chiral order parameter with increasing strength of the NNN coupling.