126 research outputs found
Diffraction of a Bose-Einstein Condensate in the Time Domain
We have observed the diffraction of a Bose-Einstein condensate of rubidium
atoms on a vibrating mirror potential. The matter wave packet bounces back at
normal incidence on a blue-detuned evanescent light field after a 3.6 mm free
fall. The mirror vibrates at a frequency of 500 kHz with an amplitude of 3.0
nm. The atomic carrier and sidebands are directly imaged during their ballistic
expansion. The locations and the relative weights of the diffracted atomic wave
packets are in very good agreement with the theoretical prediction of Carsten
Henkel et al. [1].Comment: submitted to Phys. Rev.
Diffuse reflection of a Bose-Einstein condensate from a rough evanescent wave mirror
We present experimental results showing the diffuse reflection of a
Bose-Einstein condensate from a rough mirror, consisting of a dielectric
substrate supporting a blue-detuned evanescent wave. The scattering is
anisotropic, more pronounced in the direction of the surface propagation of the
evanescent wave. These results agree very well with theoretical predictions.Comment: submitted to J Phys B, 10 pages, 6 figure
Motion analysis of a trapped ion chain by single photon self-interference
We present an optical scheme to detect the oscillations of a two-ion string
confined in a linear Paul trap. The motion is detected by analyzing the
intensity correlations in the fluorescence light emitted by one or two ions in
the string. We present measurements performed under continuous Doppler cooling
and under pulsed illumination. We foresee several direct applications of this
detection method, including motional analysis of multi-ion species or coupled
mechanical oscillators, and sensing of mechanical correlations.Comment: 6 pages, 5 figure
Single-qubit-gate error below 10^-4 in a trapped ion
With a 9Be+ trapped-ion hyperfine-states qubit, we demonstrate an error
probability per randomized single-qubit gate of 2.0(2) x 10^-5, below the
threshold estimate of 10^-4 commonly considered sufficient for fault-tolerant
quantum computing. The 9Be+ ion is trapped above a microfabricated
surface-electrode ion trap and is manipulated with microwaves applied to a trap
electrode. The achievement of low single-qubit-gate errors is an essential step
toward the construction of a scalable quantum computer.Comment: 5 pages, 3 figures, 1 table; changed to match published versio
Evanescent-wave trapping and evaporative cooling of an atomic gas near two-dimensionality
A dense gas of cesium atoms at the crossover to two-dimensionality is
prepared in a highly anisotropic surface trap that is realized with two
evanescent light waves. Temperatures as low as 100nK are reached with 20.000
atoms at a phase-space density close to 0.1. The lowest quantum state in the
tightly confined direction is populated by more than 60%. The system offers
intriguing prospects for future experiments on degenerate quantum gases in two
dimensions
- …