Bose–Einstein condensation in a mm-scale Ioffe–Pritchard trap (original) (raw)
Related papers
A gradient and offset compensated Ioffe–Pritchard trap for Bose–Einstein condensation experiments
Journal of Physics B: Atomic, Molecular and Optical Physics, 2012
The Ioffe-Pritchard trap is the workhorse of modern cold atom physics. Here, we present a novel Ioffe-Pritchard trap coil configuration based purely on circular coils. By eliminating the traditional Ioffe bars one can increase the gradient and thus the radial trapping frequency by almost a factor 2. We also present a method to achieve minimal coupling between the gradient, curvature and offset fields of the trap, thus facilitating the dynamic control of the trapping frequencies and aspect ratio.
Optically plugged quadrupole trap for Bose-Einstein condensates
Physical Review A, 2005
We created sodium Bose-Einstein condensates in an optically plugged quadrupole magnetic trap (OPT). A focused, 532nm laser beam repelled atoms from the coil center where Majorana loss is significant. We produced condensates of up to 3 × 10 7 atoms, a factor of 60 improvement over previous work [1], a number comparable to the best all-magnetic traps, and transferred up to 9 × 10 6 atoms into a purely optical trap. Due to the tight axial confinement and azimuthal symmetry of the quadrupole coils, the OPT shows promise for creating Bose-Einstein condensates in a ring geometry.
Simple method for generating Bose-Einstein condensates in a weak hybrid trap
Physical Review A, 2011
We report on a simple novel trapping scheme for the generation of Bose-Einstein condensates of 87 Rb atoms. This scheme employs a near-infrared single beam optical dipole trap combined with a weak magnetic quadrupole field as used for magneto-optical trapping to enhance the confinement in axial direction. Efficient forced evaporative cooling to the phase transition is achieved in this weak hybrid trap via reduction of the laser intensity of the optical dipole trap at constant magnetic field gradient.
2010
We demonstrate a fast production of large 23Na Bose-Einstein condensates in an optically plugged, magnetic quadrupole trap. A single global minimum of the trapping potential is generated by slightly displacing the plug beam from the center of the quadrupole field. With a dark magneto-optical trap and a simple rf evaporation, our system produces a condensate with N = 10^7 atoms every 17 s. The Majorana loss rates and the resultant heating rates for various temperatures are measured with and without plugging. The average energy of a spin-flipped atom is almost linearly proportional to temperature and determined to be about 60% of the average energy of a trapped atom. We present a numerical study of the evaporation dynamics in a plugged linear trap.
Bose-Einstein condensation in a simple microtrap
Physical Review A, 2003
A Bose-Einstein condensate is created in a simple and robust miniature Ioffe-Pritchard trap, the so-called Z trap. This trap results from the mere combination of a Z-shaped current-carrying wire and a homogeneous bias field. The experimental procedure allows condensation of typically 3ϫ10 5 87 Rb atoms in the ͉Fϭ2, m F ϭ2͘ state close to any mirroring surface, irrespective of the surface structure. Thus it is ideally suited as a simple coherent source for miniature surface traps or for cold atom physics near surfaces.
Schemes for loading a Bose Einstein condensate into a two-dimensional dipole trap
Journal of Optics B: Quantum and Semiclassical Optics, 2003
We propose two loading mechanisms of a degenerate Bose gas into a surface trap. This trap relies on the dipole potential produced by two evanescent optical waves far detuned from the atomic resonance, yielding a strongly anisotropic trap with typical frequencies 40 Hz × 65 Hz × 30 kHz. We present numerical simulations based on the time-dependent Gross-Pitaevskii equation of the transfer process from a conventional magnetic trap into the surface trap. We show that, despite a large discrepancy between the oscillation frequencies along one direction in the initial and final traps, a loading time of a few tens of milliseconds would lead to an adiabatic transfer. Preliminary experimental results are presented.
Two-component dipolar Bose-Einstein condensate in concentrically coupled annular traps
Scientific reports, 2015
Dipolar Bosonic atoms confined in external potentials open up new avenues for quantum-state manipulation and will contribute to the design and exploration of novel functional materials. Here we investigate the ground-state and rotational properties of a rotating two-component dipolar Bose-Einstein condensate, which consists of both dipolar bosonic atoms with magnetic dipole moments aligned vertically to the condensate and one without dipole moments, confined in concentrically coupled annular traps. For the nonrotational case, it is found that the tunable dipolar interaction can be used to control the location of each component between the inner and outer rings, and to induce the desired ground-state phase. Under finite rotation, it is shown that there exists a critical value of rotational frequency for the nondipolar case, above which vortex state can form at the trap center, and the related vortex structures depend strongly on the rotational frequency. For the dipolar case, it is f...
High-performance experimental apparatus for large atom number 87Rb Bose-Einstein condensates
Journal- Korean Physical Society
We describe our high-performance experimental apparatus for producing large atom number 87Rb Bose-Einstein condensates by using a double magneto-optical trap (MOT) system that consists of a two-dimensional MOT (2D MOT) and a three-dimensional MOT (3D MOT). As an atomic beam source for loading the 3D MOT, we use a unique 2D MOT system with two-color pushing beams, which increase the loading rate and the total number of atoms in the 3D MOT, compared to a pure 2D MOT by a factor of 20. After MOT compression and polarization gradient cooling, atoms are optically pumped into a magnetically trappable hyperfine state |F = 1, m F = −1〉 to be loaded into a quadrupole-Ioffe-configuration (QUIC) trap. We enhance this optical pumping process by up to 300% by using two laser beams. After rf evaporative cooling, a Bose-Einstein condensate (BEC) with more than 2 × 107 atoms is achieved.
Toroidal optical dipole traps for atomic Bose-Einstein condensates using Laguerre-Gaussian beams
2000
We theoretically investigate the use of red-detuned Laguerre-Gaussian (LG) laser beams of varying azimuthal mode index for producing toroidal optical dipole traps in two-dimensional atomic Bose-Einstein condensates. Higher-order LG beams provide deeper potential wells and tighter confinement for a fixed toroid radius and laser power. Numerical simulations of the loading of the toroidal trap from a variety of initial conditions is also given. 03.75.Fi,05.30.Jp