18 research outputs found
Transparent, Non-local, Species-selective Transport in an Optical Superlattice Containing Two Interacting Atom Species
In an optical superlattice of triple wells, containing two mutually
interacting atom species in adjacent wells, we show that one species can be
transported through the positions of the other species, yet avoiding
significant overlap and direct interaction. The transfer protocol is optimized
to be robust against missing atoms of either species in any lattice site, as
well as against lattice fluctuations. The degree and the duration of the
inter-species overlap during passage can be tuned, making possible controlled
large-scale interaction-induced change of internal states.Comment: 7 pages and 5 figure
Preparation of ultracold atom clouds at the shot noise level
We prepare number stabilized ultracold clouds through the real-time analysis
of non-destructive images and the application of feedback. In our experiments,
the atom number is determined by high precision Faraday imaging
with uncertainty below the shot noise level, i.e., . Based on this measurement, feedback is applied to reduce the atom
number to a user-defined target, whereupon a second imaging series probes the
number stabilized cloud. By this method, we show that the atom number in
ultracold clouds can be prepared below the shot noise level.Comment: Main text: 4 Figures, 4 pages. Supplemental Information: 4 figures, 5
page
Spin dynamics in a two dimensional quantum gas
We have investigated spin dynamics in a 2D quantum gas. Through spin-changing
collisions, two clouds with opposite spin orientations are spontaneously
created in a Bose-Einstein condensate. After ballistic expansion, both clouds
acquire ring-shaped density distributions with superimposed angular density
modulations. The density distributions depend on the applied magnetic field and
are well explained by a simple Bogoliubov model. We show that the two clouds
are anti-correlated in momentum space. The observed momentum correlations pave
the way towards the creation of an atom source with non-local
Einstein-Podolsky-Rosen entanglement.Comment: 5 pages, 4 figure
Utopian or Dystopian?: Using a ML-Assisted image generation game to empower the general public to envision the future
Pump-probe coupling of matter wave packets to remote lattice states
The coherent manipulation of wave packets is an important tool in many areas
of physics. We demonstrate the experimental realization of quasi-free wave
packets of ultra-cold atoms bound by an external harmonic trap. The wave
packets are produced by modulating the intensity of an optical lattice
containing a Bose-Einstein condensate. The evolution of these wave packets is
monitored in-situ and their reflection on a band gap is observed. In direct
analogy with pump-probe spectroscopy, a probe pulse allows for the resonant
de-excitation of the wave packet into localized lattice states at a long,
controllable distance of more than 100 lattice sites from the main component.
This coherent control mechanism for ultra-cold atoms thus enables controlled
quantum state preparation, opening exciting perspectives for quantum metrology
and simulation.Comment: 5 pages, 5 figure