Quantum phases and phase transitions in bosonic mixtures induced by non-s-wave Feschbach resonances in optical lattices

Laurent de Forges de Parny, V. G. Rousseau

Anatoly B. Kuklov

Feschbach resonances in a non-s-wave channel of two-component bosonic mixtures can induce atomic Bose-Einstein condensates with a nonzero orbital momentum in the optical lattice, if one component is in the Mott insulator state and the other is not. Such non-s-wave condensates break the symmetry of the lattice and, in some cases, time-reversal symmetry. They can be revealed in specific absorption imaging patterns.

Hagen M. Kleinert, Zabardast Narzikulov, Abdulla Rakhimov

D. B. M. Dickerscheid, D. van Oosten, Erik Tillema +1 more

We consider a resonantly interacting boson-fermion mixture of 40K and 87Rb atoms in an optical lattice. We show that by using a red-detuned optical lattice the mixture can be accurately described by a generalized Hubbard model for 40K and 87Rb atoms, and 40K-87Rb molecules. The microscopic parameters of this model are fully determined by the details of the optical lattice and the interspecies Feshbach resonance in the absence of the lattice. We predict a quantum phase transition to occur in this system already at low atomic filling fraction, and present the phase diagram as a function of the temperature and the applied magnetic field.

Pierfrancesco Buonsante, S. M. Giampaolo, Fabrizio Illuminati +2 more

Haiming Deng, Zhi Tan, Chao Kong +2 more

Motivated by the recent experiment on bosonic mixtures of atoms and molecules, we investigate pairing superfluid–insulator (SI) transition for bosonic mixtures of atoms and molecules in a one-dimensional optical lattice, which is described by an extended Bose–Hubbard model with atom–molecule conservation (AMC). It is found that AMC can induce an extra pair–superfluid phase though the system does not demonstrate pair-hopping. In particular, the system may undergo several pairing SI or insulator–superfluid transitions as the detuning from the Feshbach resonance is varied from negative to positive, and the larger positive detuning can bifurcate the pair–superfluid phases into mixed superfluid phases consisting of single-atomic and pair-atomic superfluid. The calculation of the second-order Rényi entropy reveals that the discontinuity in its first-order derivative corresponds to the phase boundary of the pairing SI transition. This means that the residual entanglement in our mean-field treatment can be used to efficiently capture the signature of the pairing SI transition induced by AMC.