title: Three-sublattice ordering of the SU(3) Heisenberg model of three-flavor fermions on the square and cubic lattices.
abstract: Combining a semiclassical analysis with exact diagonalizations, we show that the ground state of the SU(3) Heisenberg model on the square lattice develops three-sublattice long-range order. This surprising pattern for a bipartite lattice with only nearest-neighbor interactions is shown to be the consequence of a subtle quantum order-by-disorder mechanism. By contrast, thermal fluctuations favor two-sublattice configurations via entropic selection. These results are shown to extend to the cubic lattice, and experimental implications for the Mott-insulating states of three-flavor fermionic atoms in optical lattices are discussed.
authors.affiliation: Institut de théorie des phénomènes physiques, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
authors.forename: Tamás A
authors.initials: TA
authors.lastname: Tóth
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Läuchli
authors.forename: Frédéric
authors.initials: F
authors.lastname: Mila
authors.forename: Karlo
authors.initials: K
authors.lastname: Penc