Aligned dipolar Bose-Einstein condensate in a double-well potential: From cigar-shaped to pancake-shaped

Abstract

We consider a Bose-Einstein condensate (BEC), which is characterized by long-range and anisotropic dipole-dipole interactions and vanishing s-wave scattering length, in a double-well potential. The properties of this system are investigated as functions of the height of the barrier that splits the harmonic trap into two halves, the number of particles (or dipole-dipole strength) and the aspect ratio $\lambda$, which is defined as the ratio between the axial and longitudinal trapping frequencies ${\omega }_z$ and ${\omega }_{\rho }$. The phase diagram is determined by analyzing the stationary mean-field solutions. Three distinct regions are found: a region where the energetically lowest lying stationary solution is symmetric, a region where the energetically lowest lying stationary solution is located asymmetrically in one of the wells, and a region where the system is mechanically unstable. For sufficiently large aspect ratio $\lambda$ and sufficiently high barrier height, the system consists of two connected quasi-two-dimensional sheets with density profiles whose maxima are located either at $\rho =0$ or away from $\rho =0$. The stability of the stationary solutions is investigated by analyzing the Bogoliubov de Gennes excitation spectrum and the dynamical response to small perturbations. These studies reveal unique oscillation frequencies and distinct collapse mechanisms. The results derived within the mean-field framework are complemented by an analysis based on a two-mode model.

21 pages, 16 figures

References in corpus (21)

• Many-Body Physics with Ultracold Gases
• Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
• A High Phase-Space-Density Gas of Polar Molecules
• Bose-Einstein condensation of chromium
• Spontaneous symmetry breaking in a quenched ferromagnetic spinor Bose condensate
• Squeezing and entanglement in a Bose-Einstein condensate
• Observation of dipole-dipole interaction in a degenerate quantum gas
• Stabilizing a purely dipolar quantum gas against collapse
• Quantum Gas of Deeply Bound Ground State Molecules
• d-wave collapse and explosion of a dipolar Bose-Einstein condensate
• Spontaneously modulated spin textures in a dipolar spinor Bose-Einstein condensate
• Radial and angular rotons in trapped dipolar gases
• Bogoliubov modes of a dipolar condensate in a cylindrical trap
• Stability of quasi-two-dimensional Bose-Einstein condensates with dominant dipole-dipole interactions
• Metastable states of a gas of dipolar bosons in a 2D optical lattice
• Magnetic dipolar interaction in an atomic Bose Einstein condensate interferometer
• Symmetry Breaking and Self-trapping of a Dipolar Bose-Einstein Condensate in a Double-well Potential
• Ground-state structure and stability of dipolar condensates in anisotropic traps
• Angular collapse of dipolar Bose-Einstein condensates
• Coherent collapse of a dipolar Bose-Einstein condensate for different trap geometries
• Vortex in a trapped Bose-Einstein condensate with dipole-dipole interactions

Cited by in corpus (20)

• Fortran and C programs for the time-dependent dipolar Gross-Pitaevskii equation in an anisotropic trap
• Mesoscopic ensembles of polar bosons in triple-well potentials
• Dipolar condensates confined in a toroidal trap: ground state and vortices
• A dipolar self-induced bosonic Josephson junction
• Roton excitations in a trapped dipolar Bose-Einstein condensate
• Dipolar Bose-Einstein condensates in a PT-symmetric double-well potential
• Dipolar Bose-Einstein condensate soliton on a two-dimensional optical lattice
• Quantum dynamics of few dipolar bosons in a double-well potential
• Bifurcations and exceptional points in a PT-symmetric dipolar Bose-Einstein condensate
• Winding number dependence of Bose-Einstein condensates in a ring-shaped lattice
• A dipolar droplet bound in a trapped Bose-Einstein condensate
• Modification of roton instability due to the presence of a second dipolar Bose-Einstein condensate
• Dipolar Bose-Einstein condensates in triple-well potentials
• Two-mode dipolar bosonic junctions
• Rotational properties of non-dipolar and dipolar Bose-Einstein condensates confined in annular potentials
• Quantum correlations of few dipolar bosons in a double-well trap
• Tuning the structural and dynamical properties of a dipolar Bose-Einstein condensate: Ripples and instability islands
• Effects of Long-Range Nonlinear Interactions in Double-Well Potentials
• Dipolar Bose-Einstein condensate for large scattering length
• Torus-like solutions for the Landau-de Gennes model. Part III: torus vs split minimizers