Paired phases of bosons in optical lattices

S. L. Rolston

Suman Mondal, Sebastian Greschner, Tapan Mishra

We analyze the ground-state properties of three-body constrained bosons in a one-dimensional optical lattice with staggered hoppings analogous to the double-well optical lattice. By considering attractive and repulsive on-site interactions between the bosons, we obtain the phase diagram which exhibits various quantum phases. Due to the double-well geometry and three-body constraint, several gapped phases such as the Mott insulators and dimer--bond-order phases emerge at commensurate densities in the repulsive interaction regime. Attractive interaction leads to the pair formation which leads to the pair--bond-order phase at unit filling, which resembles the valence-bond solid phase of composite bosonic pairs. At incommensurate densities, we see the signatures of the gapless pair superfluid phase.

Jian Li, Yupeng Wang

A t–J1–J2 model is constructed to describe the spin-1 bosons in optical lattices in the strong correlation limit. In the parameter region of J1<J2, with the slave-boson-mean-field approach, it is found that two kinds of condensed phases may exist: a condensate with spin singlet pairs and a condensate with ferro-quadruple long range order coexisting with singlet pairs. A first-order quantum phase transition occurs at the point J1 = 0. The finite-temperature phase transition in a cubic optical lattice was also discussed.

Daniel S. Goldbaum, Erich J. Mueller

Michael Aizenman, Elliot H. Lieb, Robert Seiringer +2 more

María Eckholt, Juan José García‐Ripoll

We design a model of correlated hopping for bosonic atoms in optical lattices. Such a model exhibits three kinds of phases: a Mott insulator, a charge density wave, and a pair quasicondensate. One possible implementation of the model is based on two-state atoms embedded in an optical superlattice and having state-dependent interactions. Contrary to other models of pairing, correlated hopping is not a perturbative effect and should be observable in generalizations of current experiments.