Collinear ordering of easy-axis triangular lattice antiferromagnets

Abstract

Antiferromagnetically coupled moments on the frustrated triangular lattice typically order in a coplanar state at low temperature. Here, we demonstrate that the presence of not-very-large easy axis single ion anisotropy leads to an interesting orientationally ordered collinear state in triangular lattice antiferromagnets with moments $S\ge 3/2$. This ordered state breaks the symmetry of $\ddot{I}€/3$ rotations about a lattice site, while leaving intact the translational symmetry of the lattice.

4 pages, 2-column format, 3 .eps figures