An off-axis rotating atom trap (original) (raw)

Characterization of cold atomic cloud in a magneto-optical trap

2011

The results of characterization of cold cloud of cesium (Cs) atoms trapped in a magneto-optical trap (MOT) have been presented. The MOT is a part of the Physics package of the Cs Fountain Clock being developed at National Physical Laboratory (NPL), India. The number of atoms, size and temperature of the cloud have been measured and calculated. It is also been investigated how the number of trapped atoms changes with the trapping laser’s beam intensity, detuning and magnetic-field gradient of the trap.

A lattice of magneto-optical and magnetic traps for cold atoms

2003

Basic periodic trapping configurations is presented, which can be realized with multilayer microstructures. The trapping fields for the atoms (Ioffe Pritchard type potentials for magnetic trapping of atoms as well as quadrupole fields for magneto-optical trapping) are formed by two layers of crossed wires, which can be individually addressed. The possibility of producing multiple magneto optical traps (MOT) next to a surface in a controlled manner will be shown. This could be a first step to load ultracold atoms into an array of microstructured magnetic traps in a parallel way.

A hybrid laser-magnet trap for spin-polarized atoms

Progress in Quantum Electronics, 1984

This paper presents a brief survey of theoretical issues related to a hybrid laser-magnet trap for neutral spin-polarized atoms. At low densities, such a trap might be used to address a number of fundamental questions, e.g. the interaction of an individual atom with an electromagnetic field, while at high densities it might be used for "containerless" preparation of bulk amounts of a new metastable form of matter, spin-polarized atoms. In particular, a discussion is presented of the feasibility and limitations of a trap based on a near-resonant CW TEM]I ("doughnut mode") laser beam, which provides trapping in two dimensions, and on a strong homogeneous solenoidal magnetic field (the axis of which is also the laser axis), which provides trapping in the third dimension.

Hexapole-compensated magneto-optical trap on a mesoscopic atom chip

Physical Review A, 2011

Magneto-optical traps on atom chips are usually restricted to small atomic samples due to a limited capture volume caused primarily by distorted field configurations. Here we present a magneto-optical trap with minimized distortions based on a mesoscopic wire structure which provides a loading rate of 8.4 × 10 10 atoms/s and a maximum number of 8.7 × 10 9 captured atoms. The wire structure is placed outside of the vacuum to enable a further adaptation to new scientific objectives. Since all magnetic fields are applied locally without the need for external bias fields, the presented setup will facilitate parallel generation of Bose-Einstein condensates on a conveyor belt with a cycle rate above 1 Hz.

Two-dimensional magneto-optical trap as a source of slow atoms

Physical Review A, 1998

We experimentally study the use of two-dimensional magneto-optical trapping ͑2D-MOT͒ for the generation of slow beams of cold atoms out of a vapor cell. A particularly high flux of 9ϫ10 9 rubidium atoms/s at a mean velocity of 8 m/s is obtained using a combination of magneto-optical trapping in two dimensions and Doppler cooling in the third dimension (2D ϩ-MOT͒. The resulting width of the velocity distribution is 3.3 m/s ͓full width at half maximum ͑FWHM͔͒ with a beam divergence of 43 mrad ͑FWHM͒. We investigate the total flux as a function of vapor cell pressure and determine the velocity distribution of our slow atom sources. For comparison, we also realized a low-velocity intense source ͑LVIS͒, first reported by Lu et al. ͓Phys. Rev. Lett. 77, 3331 ͑1996͔͒. We find that the 2D ϩ-MOT yields a significantly higher flux than the LVIS, even when used with an order of magnitude less laser power.

Dynamics in a two-level atom magneto-optical trap

Physical Review A, 2002

Alkaline-earth-metal atoms present an ideal platform for exploring magneto-optic trap ͑MOT͒ dynamics, enabling unique and definitive tests of laser cooling and trapping mechanisms. We have measured the trapping beam intensity, detuning, magnetic-field gradient, trap density, and lifetime dependence of the spring constant and damping coefficient ␣ for a 1 S 0-1 P 1 88 Sr MOT by fitting the oscillatory response of the atom cloud to a step-function force. We find that the observed behavior of and ␣ provide a unified and consistent picture of trap dynamics that agrees with Doppler cooling theory at the level of 10%. Additionally, we demonstrate that the trapped atom temperature can be determined directly from measured value of and the trap size, in excellent agreement with free-expansion temperature measurements. However, the experimentally determined temperature is much higher than Doppler cooling theory, implying significant additional heating mechanisms.

Novel Optical Trap of Atoms with a Doughnut Beam

Physical Review Letters, 1997

We have constructed a novel optical trap for neutral atoms by using a Laguerre-Gaussian (doughnut) beam whose frequency is blue detuned to the atomic transition. Laser-cooled rubidium atoms are trapped in the dark core of the doughnut beam with the help of two additional laser beams which limit the atomic motion along the optical axis. About 10 8 atoms are initially loaded into the trap, and the lifetime is 150 ms. Because the atoms are confined at a point in a weak radiation field in the absence of any external field, ideal circumstances are provided for precision measurements. The trap opens the way to a simple technique for atom manipulation, including Bose-Einstein condensation of gaseous atoms.

Optical diagnostics of cold (T<1mK) atoms in the magneto-optical trap

2003

Cooling and trapping neural atoms with laser beams became a standard method of studying atom properties in temperatures close to absolute zero. Precise knowledge of physical parameters of the atomic sample is of prime importance in such studies, particularly the knowledge of the number of trapped atoms, their density and temperature. Diagnostics aiming at determination of these parameters has to

Permanent magnet trap for cold atoms

Physical Review A, 1995

We report the trapping of neutral atoms in a permanent magnet trap. Approximately 1X10 ground-state lithium atoms have been confined in a nonzero magnetic-field minimum produced by six permanent magnets in an Ioffe configuration. These atoms have a kinetic temperature of 1.1 mK and a peak density of approximately 3 X 10 cm. The trapped-atom lifetime is 240 s, limited by collisions with background gas. This trap provides an environment in which quantum-statistical effects, atomic collisions, and other ultralow-temperature phenomena can be studied.

Optimized magneto-optical trap for experiments with ultracold atoms near surfaces

Physical Review A, 2004

We present an integrated wire-based magnetooptical trap for the simplified trapping and cooling of large numbers of neutral atoms near material surfaces. With a modified U-shaped current-carrying Cu structure we collect > 3 × 10 8 87 Rb atoms in a mirror MOT without using quadrupole coils. These atoms are subsequently loaded to a Z-wire trap where they are evaporatively cooled to a Bose-Einstein condensate close to the surface.