Chiral phase of the Heisenberg antiferromagnet with a triangular lattice
Abstract
In the presence of nexttonearestneighbor exchange interaction the classical ground state of the Heisenberg antiferromagnet with a triangular lattice in a wide domain of parameters has a foursublattice structure. This ground state is highly degenerate: the only restriction for the spins on four sublattices is that their sum should be equal to zero. The accidental degeneracy is removed by fluctuations or nonbilinear interactions of spins. Fluctuations (quantum or thermodynamical) favor the collinear arrangement of spins, but a fourspin exchange interaction favors a nonplanar configuration that can be characterized by positive or negative chirality. In the presence of such an interaction the longrange order in chiralities will survive up to some finite temperature although the longrange order in spin variables will be destroyed by fluctuations at an arbitrarily low temperature.
 Publication:

Physical Review B
 Pub Date:
 March 1993
 DOI:
 10.1103/PhysRevB.47.6165
 Bibcode:
 1993PhRvB..47.6165K
 Keywords:

 75.10.b;
 75.40.Cx;
 75.50.Ee;
 64.60.Cn;
 General theory and models of magnetic ordering;
 Static properties;
 Antiferromagnetics;
 Orderdisorder transformations;
 statistical mechanics of model systems