Stability of Superfluid and Supersolid Phases of Dipolar Bosons in Optical Lattices (original) (raw)
Related papers
Quantum Phases of Dipolar Bosons in Optical Lattices
Physical Review Letters, 2002
The ground state of dipolar bosons placed in an optical lattice is analyzed. We show that the modification of experimentally accessible parameters can lead to the realization and control of different quantum phases, including superfluid, supersolid, Mott insulator, checkerboard, and collapse phases.
Superfluid phases of spin-1 bosons in a cubic optical lattice
Laser Physics Letters, 2013
We analyze theoretically the emergence of different superfluid phases of spin-1 bosons in a three-dimensional cubic optical lattice by generalizing the recently developed Ginzburg-Landau theory for the Bose-Hubbard model to a spinor Bose gas. In particular at zero temperature, our theory distinguishes within its validity range between various superfluid phases for an anti-ferromagnetic interaction with an external magnetic field. In addition, we determine that the superfluid-Mott insulator phase transition is of second order and that the transitions between the respective superfluid phases with anti-ferromagnetic interaction can be both of first and second order.
Creation of a Dipolar Superfluid in Optical Lattices
Physical Review Letters, 2003
We show that by loading a Bose-Einstein condensate (BEC) of two different atomic species into an optical lattice, it is possible to achieve a Mott-insulator phase with exactly one atom of each species per lattice site. A subsequent photo-association leads to the formation of one heteronuclear molecule with a large electric dipole moment, at each lattice site. The melting of such dipolar Mott-insulator creates a dipolar superfluid, and eventually a dipolar molecular BEC.
New Deep Superfluid Phases of Spin-1 Bosons in Optical Lattice
Journal of Low Temperature Physics, 2018
We analyse theoretically a spin-1 Bose gas loaded into a three-dimensional optical lattice in order to emerge different superfluid phases with external magnetic field. To achieve this, we generalize the mean-field perturbation theory up to the sixth hopping order for the underlying spin-1 Bose-Hubbard model. Our results indicate that the condensate density can be valid deep in the superfluid phase in comparison with that of the fourth hopping order. At zero temperature, new deep superfluid phases for an anti-ferromagnetic interaction are determined in the presence of the external magnetic field. Moreover, we find the second-order quantum phase transition between Mott insulator and superfluid phase for both ferromagnetic and anti-ferromagnetic interactions. Within the anti-ferromagnetic interaction, the transitions between respective superfluid phases can be of the first order.
Quantum phases of constrained dipolar bosons in coupled one-dimensional optical lattices
Physical Review A
We investigate a system of two-and three-body constrained dipolar bosons in a pair of onedimensional optical lattices coupled to each other by the non-local dipole-dipole interactions. Assuming attractive dipole-dipole interactions, we obtain the ground state phase diagram of the system by employing the cluster mean-field theory. The competition between the repulsive on-site and attractive nearest-neighbor interactions between the chains yields three kinds of superfluids; namely the trimer superfluid, pair superfluid and the usual single particle superfluid along with the insulating Mott phase at the commensurate density. Besides, we also realize simultaneous existence of Mott insulator and superfluid phases for the two-and three-body constrained bosons, respectively. We also analyze the stability of these quantum phases in the presence of a harmonic trap potential.
Staggered-Vortex Superfluid of Ultracold Bosons in an Optical Lattice
Physical Review Letters, 2008
We show that the dynamics of cold bosonic atoms in a two-dimensional square optical lattice produced by a bichromatic light-shift potential is described by a Bose-Hubbard model with an additional effective staggered magnetic field. In addition to the known uniform superfluid and Mott insulating phases, the zero-temperature phase diagram exhibits a novel kind of finite-momentum superfluid phase, characterized by a quantized staggered rotational flux. An extension for fermionic atoms leads to an anisotropic Dirac spectrum, which is relevant to graphene and high-Tc superconductors.
Quantum phases of hard-core dipolar bosons in coupled one-dimensional optical lattices
Physical Review A, 2014
Hard-core dipolar bosons trapped in a parallel stack of N ≥ 2 1D optical lattices (tubes) can develop several phases made of composites of particles from different tubes: superfluids, supercounterfluids and insulators as well as mixtures of those. Bosonization analysis shows that these phases are threshold-less with respect to the dipolar interaction, with the key "control knob" being filling factors in each tube, provided the inter-tube tunneling is suppressed. The effective ab-initio quantum Monte Carlo algorithm capturing these phases is introduced and some results are presented. arXiv:1405.4328v1 [cond-mat.other]
Coexistence of superfluid and Mott phases of lattice bosons
Physical Review A, 2007
Recent experiments on strongly-interacting bosons in optical lattices have revealed the coexistence of spatially-separated Mott-insulating and number-fluctuating phases. The description of this inhomogeneous situation is the topic of this Letter. We establish that the number-fluctuating phase forms a superfluid trapped between the Mott-insulating regions and derive the associated collective mode structure. We discuss the interlayer's crossover between two-and three-dimensional behavior as a function of the lattice parameters and estimate the critical temperatures for the transition of the superfluid phase to a normal phase.
2012
The supersolid (SS) is an intriguing but counterintuitive concept, for it is characterized by the coexistence of a diagonal long-range order (DLRO) of a solid and an off-diagonal long-range order (ODLRO) of a superfluid (SF). The possible existence of the SS phase has been studied experimentally and theoretically since the early 1970s. 1–3 In recent years, numerical simulations have established the existence of the SS phase in a number of interacting lattice boson models.