Antiferromagnetic XY model on a triangular lattice: ordered states in a magnetic field

Korshunov S. E.

**The structure of ordered states of a two-dimensional planar antiferromagnet (with a triangular lattice) in a magnetic field is analyzed. Incorporating the free energy of spin waves lifts the continuous degeneracy. A phase diagram is constructed. It contains (in contrast with that in the absence of a magnetic field) four distinct ordered phases.**