MONTE-CARLO SIMULATION OF THE EASY-AXIS ANTIFERROMAGNETIC HEISENBERG-MODEL ON A STACKED TRIANGULAR LATTICE

Preliminary results are presented of a Monte Carlo simulation to study the easy-axis hexagonal antiferromagnet in a magnetic field applied along the c axis. A wide variety of magnetic phases can be stabilized which are characterized by a period-two modulation along the c axis and a period-three modulation in the basal plane. For sufficiently strong single-ion anisotropy, an Ising-like state is realized where one-third of spins are ferromagnetically coupled between planes and which has an infinitely degenerate ground state.