Elife Karabulut

Density-Functional Theory for Strongly Correlated Bosonic and Fermionic Ultracold Dipolar and Ionic Gases

We introduce a density functional formalism to study the ground-state properties of strongly correlated dipolar and ionic ultracold bosonic and fermionic gases, based on the self-consistent combination of the weak and the strong coupling limits. Contrary to conventional density functional approaches, our formalism does not require a previous calculation of the interacting homogeneous gas, and it is thus very suitable to treat systems with tunable long-range interactions. Because of its asymptotic exactness in the regime of strong correlation, the formalism works for systems in which standard mean-field theories fail.

Spin–orbit-coupled Bose–Einstein-condensed atoms confined in annular potentials

A spin-orbit-coupled Bose-Einstein-condensed cloud of atoms confined in an annular trapping potential shows a variety of phases that we investigate in the present study. Starting with the non-interacting problem, the homogeneous phase that is present in an untrapped system is replaced by a sinusoidal density variation in the limit of a very narrow annulus. In the case of an untrapped system there is another phase with a striped-like density distribution, and its counterpart is also found in the limit of a very narrow annulus. As the width of the annulus increases, this picture persists qualitatively. Depending on the relative strength between the inter- and the intra-components, interactions either favor the striped phase, or suppress it, in which case either a homogeneous, or a sinusoidal-like phase appears. Interactions also give rise to novel solutions with a nonzero circulation.

Rotational properties of nondipolar and dipolar Bose-Einstein condensates confined in annular potentials

We investigate the rotational response of both nondipolar and dipolar Bose-Einstein condensates confined in an annular potential via minimization of the energy in the rotating frame. For the nondipolar case we identify certain phases which are associated with different vortex configurations. For the dipolar case, assuming that the dipoles are aligned along some arbitrary and tunable direction, we study the same problem as a function of the orientation angle of the dipole moment of the atoms. DOI: 10.1103/PhysRevA.87.033615

Wigner-localized states in spin-orbit-coupled bosonic ultracold atoms with dipolar interaction

We investigate the occurence of Wigner-localization phenomena in bosonic dipolar ultracold few-body systems with Rashba-like spin-orbit coupling. We show that the latter strongly enhances the effects of the dipole-dipole interactions, allowing to reach the Wigner-localized regime for strengths of the dipole moment much smaller than those necessary in the spin-orbit-free case.

Phase diagram of a rapidly rotating two-component Bose gas

We derive analytically the phase diagram of a two-component Bose gas confined in an anharmonic potential, which becomes exact and universal in the limit of weak interactions and small anharmonicity of the trapping potential. The transitions between the different phases, which consist of vortex states of single and multiple quantization, are all continuous because of the addition of the second component. DOI: 10.1103/PhysRevA.87.043609