Crystallization of trions in SU(3) cold-atom gases trapped in optical lattices

Abstract

Cold fermionic atoms with three different hyperfine states confined in optical lattices show pronounced atomic density waves (ADWs). These ADWs are pinned due to the confining potential that traps the atoms in the optical lattice and can be considered a crystal phase of strongly bound trions (CPT). We show that the crystalline phase is incompressible and robust against anisotropic interactions. We also show that it is generic in the presence of the trap due to its incompressibility. Numeric density matrix renormalization group calculations show evidence of a crossover between a trionic superfluid and the CPT state as a function of the strength of the interaction and as a function of the anisotropy of the interaction. © 2009 The American Physical Society.