SKYRME CRYSTAL IN A 2-DIMENSIONAL ELECTRON-GAS

The ground state of a two-dimensional electron gas at Landau level fil ling factors near nu = 1 is a Skyrme crystal with long-range order in the positions and orientations of the topologically and electrically c harged elementary excitations of the nu = 1 ferromagnetic ground state . The lowest energy Skyrme crystal is a square lattice with opposing p ostures for topological excitations on opposite sublattices. The filli ng factor dependence of the electron spin polarization, calculated for the square lattice Skyrme crystal, is in excellent agreement with rec ent experiments.