The Kagome Antiferromagnet with Defects: Satisfaction, Frustration, and Spin Folding in a Random Spin System

摘要

It is shown that site disorder induces noncoplanar states, competing with thethermal selection of coplanar states, in the nearest neighbor, classical kagomeHeisenberg antiferromagnet (AFM). For weak disorder, it is found that theground state energy is the sum of energies of separately satisfied triangles ofspins. This implies that disorder does not induce conventional spin glassbehavior. A transformation is presented, mapping ground state spinconfigurations onto a folded triangular sheet (a new kind of ``spin origami'')which has conformations similar to those of tethered membranes.