Mott transitions of three-component fermionic atoms with repulsive interaction in optical lattices

Abstract

We investigate the Mott transitions of three-component (colors) repulsive fermionic atoms in optical lattices using the dynamical mean-field theory. We find that for SU(3) symmetry-breaking interactions, the Mott transition occurs at incommensurate half filling. As a result, a characteristic Mott insulating state appears, where paired atoms with two different colors and atoms with the third color are localized, and either of these states is randomly distributed in each site. We also find another Mott state, where atoms with two different colors are randomly localized at different sites, and atoms with the third color remain itinerant. We demonstrate that double occupancy measurements show characteristics of these exotic Mott phases.

Stability of the superfluid state in three-component fermionic optical lattice systems

“…This implies that the Mott insulating state is realized for colors 1 and 2 and free fermion behavior survives for color 3. Therefore, this state can be regarded as the color selective Mott (CSM) state [17]. By contrast, when U < U p , D 23 and Z 3 are rapidly decreased upon the introduction of the interaction U , as shown in Figs.…”

Mott transitions in a three-component Falicov-Kimball model: A slave boson mean-field study

“…The model can also be considered as an extreme mass imbalance case of the three-component fermion Hubbard model [4,5], or a multicomponent extension of the spinless FKM [24]. It has two well-known limiting cases.…”

“…In this MIT, all atoms of both species equally participate in the transition. Like in the three-component Hubbard model [4,5], the MIT is referred to as the collective MIT [21]. The filling n c = 3/4 can be considered as a particle-hole symmetry of filling n c = 1/4 [21].…”

Controlled pairing symmetry of the superfluid state in systems of three-component repulsive fermionic atoms in optical lattices

“…When two of the three repulsions are stronger than the other, pairs of weakly repulsing atoms are formed to avoid the two stronger repulsions. This Mott state is called the paired Mott insulator (PMI) [22]. When two of the three repulsions are weaker than the other, atoms with the strongest repulsion undergo a Mott transition while atoms with the remaining color stay a Fermi liquid.…”

“…When two of the three repulsions are weaker than the other, atoms with the strongest repulsion undergo a Mott transition while atoms with the remaining color stay a Fermi liquid. This state is called the color-selective Mott state (CSM) [21,22]. In the ground state at half filling, two kinds of the staggered ordered states appear in the respective parameter regions: a color-density wave (CDW) and a color-selective antiferromagnet (CSAF) [21].…”