KAGOME ANTIFERROMAGNET WITH DEFECTS - SATISFACTION, FRUSTRATION, AND SPIN FOLDING IN A RANDOM SPIN SYSTEM

It is shown that site disorder induces noncoplanar states, competing w ith the thermal selection of coplanar states, in the nearest neighbor, classical Kagome Heisenberg antiferromagnet. For weak disorder, it is found that the ground state energy is the sum of energies of separate ly satisfied triangles of spins. This implies that disorder does not i nduce conventional spin glass behavior. A transformation is presented, mapping ground state spin configurations onto a folded triangular she et (a new kind of ''spin origami'') which has conformations similar to those of tethered membranes.