We propose several schemes for implementing a fast two-qubit quantum gate neutral atoms with the operation time much faster than scales associated external motion of in trapping potential. In our example, large interaction energy required to perform operations is provided by dipole-dipole excited low-lying Rydberg states constant electric fields. A detailed analysis imperfections given.

Quantum phase engineering is demonstrated with two techniques that allow the spatial distribution of a Bose-Einstein condensate (BEC) to be written and read out. A quantum state was designed produced by optically imprinting pattern onto BEC sodium atoms, matter-wave interferometry spatially resolved imaging used analyze resultant distribution. An appropriate imprint created solitons, first experimental realization this nonlinear phenomenon in BEC. The subsequent evolution these excitations...

We have observed Bragg diffraction of a Bose-Einstein condensate sodium atoms by moving, periodic, optical potential. The coherent process produced splitting the with unidirectional momentum transfer. Using selectivity process, we separated component width narrower than that original condensate. By repeatedly pulsing potential while were trapped, trajectory split atomic wave packets in confining magnetic

Extraction of sodium atoms from a trapped Bose-Einstein condensate (BEC) by coherent, stimulated Raman process is demonstrated. Optical pulses drive transitions between and untrapped magnetic sublevels, giving the output-coupled BEC fraction well-defined momentum. The pulsed output coupling can be run at such rate that extracted atomic wave packets strongly overlap, forming highly directional, quasi-continuous matter wave.

We report the creation of an ultracold neutral plasma by photoionization laser-cooled xenon atoms. The charge carrier density is as high $2\ifmmode\times\else\texttimes\fi{}{10}^{9}{\mathrm{cm}}^{\ensuremath{-}3}$, and temperatures electrons ions are low 100 mK $10\ensuremath{\mu}\mathrm{K}$, respectively. Plasma behavior evident in trapping positive ion cloud when Debye screening length becomes smaller than size sample. produce plasmas with parameters such that both strongly coupled.

We investigate the correlation properties of a one-dimensional interacting Bose gas by loading magnetically trapped 87Rb Bose-Einstein condensate (BEC) into deep two-dimensional optical lattice. measure three-body recombination rate for both BEC in magnetic trap and loaded The coefficient is factor 7 smaller lattice, which we interpret as reduction local function 1D case. This signature intermediate between that uncorrelated, phase coherent, 1D, mean-field regime strongly correlated...

We present a summary of the results simple two-level theory Doppler cooling in optical molasses and contrast it with recent theories multilevel, polarization-gradient cooling. The effects single-photon recoil trapping microscopic potential wells are also considered. Experiments described which temperature sodium atoms released from is measured found to be well below Doppler-cooling limit. Measurements dependence on many experimental parameters good qualitative agreement new

Atoms interact with each other through the electromagnetic field, creating collective states that can radiate faster or slower than a single atom, i.e. super- and sub-radiance. The generation control of such by engineering dipolar interactions between atoms enable new tools for atomic-based technologies. Atom-atom in free space are limited range, since amplitude radiated field decreases inversely distance. When is confined to one dimension it enables infinite-range interactions. This has...

We have performed a number of experiments with Bose-Einstein condensate (BEC) in one dimensional optical lattice. Making use the small momentum spread BEC and standard atom optics techniques high level coherent control over an artificial solid state system is demonstrated. are able to load into lattice ground very efficiency by adiabatically turning on coherently transfer population between states observe their evolution. Methods developed used perform band spectroscopy. these build...

We observe transitions of laser-cooled Rb between vibrational levels in subwavelength-sized optical potential wells, using high-resolution spectroscopy resonance fluorescence. measure the spacing and population distribution, find atoms to be localized 1/15 wavelength. up 60% trapped ground state. The dependence spectrum on parameters field provides detailed information about dynamics atoms.

We localize Cs atoms in wavelength-sized potential wells of an optical lattice, and cool them to a three-dimensional temperature 700 nK by adiabatic expansion. In the lattice we precool $\ensuremath{\approx}1\ensuremath{\mu}\mathrm{K}$. then reduce trapping few hundred $\ensuremath{\mu}$s, causing atomic center-of-mass distribution expand decrease amount which agrees with simple 3D band theory. These are lowest kinetic temperatures ever measured.

We study the formation of Rydberg atoms in expanding plasmas at temperatures 1-1000 K and densities from 10(5)-10(10) cm(-3). Up to 20% initially free charges recombine about 100 micros, binding energy approximately equals increase kinetic remaining electrons. Three-body recombination is expected dominate this regime, yet most our results are inconsistent with mechanism.

We have observed the spectrum of long range molecular states singly excited ${\mathrm{Na}}_{2}$ formed by photoassociation during ultracold associative ionization collisions laser-cooled Na atoms. The low kinetic energy collision allows us to obtain very high resolution spectra and observe close dissociation limit. shows regular vibrational series characteristic 1/${\mathit{R}}^{3}$ portion ${1}_{\mathit{g}}$ potential (asymptotically ${\mathit{S}}_{1/2}$+${\mathit{P}}_{3/2}$) as well...

Lithography can be performed with beams of neutral atoms in metastable excited states to pattern self-assembled monolayers (SAMs) alkanethiolates on gold. An estimated exposure a SAM dodecanethiolate (DDT) 15 20 argon per DDT molecule damaged the sufficiently allow penetration an aqueous solution ferricyanide surface This etched gold and transformed patterns SAMs into structures gold; these had edge resolution less than 100 nanometers. Regions as large 2 square centimeters were patterned by...

We have developed a technique to control the placement of atoms in an optical lattice by using superlattice comprising two separately manipulated, periodic potentials with commensurate periods. demonstrate selective loading Bose-condensed ${}^{87}\mathrm{Rb}$ into every third site one-dimensional lattice. Our provides wide separation yet tight confinement, useful properties for neutral-atom implementations quantum computing. Interference released from and Bragg reflection reveal confinement...

We report the observation of plasma oscillations in an ultracold neutral plasma. With this collective mode we probe electron density distribution and study expansion as a function time. For classical conditions, i.e., weak Coulomb coupling, is dominated by pressure gas described hydrodynamic model. Discrepancies between model observations at low temperature high may be due to strong coupling electrons.

We report the observation of strongly damped dipole oscillations a quantum degenerate 1D atomic Bose gas in combined harmonic and optical lattice potential. Damping is significant for very shallow axial lattices (0.25 photon recoil energies), increases dramatically with increasing depth, such that becomes nearly immobile times an order magnitude longer than single-particle tunneling time. Surprisingly, we see no broadening quasimomentum distribution after motion. Recent theoretical work...

We analyze and experimentally demonstrate a new (temporal) Talbot effect, where pulsed phase grating is applied to cloud of cold atoms (Bose-Einstein condensate). In contrast the usual (spatial) our gain kinetic energy when diffracted by grating. The matter-wave-dispersion relation result in an exact (no paraxial approximation) effect initial wave front reconstructed at multiples ``Talbot time'' ${T}_{\mathrm{T}}$. applying second after variable delay. When this even (odd)...

We observe coherently enhanced reflection (Bragg scattering) of a near resonant laser beam from cesium atoms ordered by periodic array optical potential wells known as an lattice. The reflected light is factor $\ensuremath{\sim}{10}^{5}$ over scattering disordered atomic sample. measure the magnitude reflectivity and its detuning dependence functions density degree localization atoms. change in lattice constant due to frequency-dependent effective index refraction seen field observed.

Antiprotons from the Low Energy Antiproton Ring of CERN are slowed 21 MeV to below 3 keV by being passed through mm material, mostly Be. While still in flight, kiloelectronvolt antiprotons captured a Penning trap created sudden application 3-kV potential. held for 100 s and more. Prospects now excellent much longer trapping times under better vacuum conditions. This demonstrates feasibility greatly improved measurement inertial mass antiproton opens way other intriguing experiments.

We study photonic band gaps in a one-dimensional optical lattice of laser-cooled trapped atoms. solve for the self-consistent equilibrium positions atoms, accounting backaction atoms on trapping beams. This solution depends strongly sign laser detuning. For red-detuned lasers, resulting exhibits gap frequencies between frequency and atomic resonance. blue detuning stop extends symmetrically about resonance, typically hundreds linewidths, except small region resonance frequency, which is...