In December our group was joined by Lars Wacker, who previously did his Diploma Thesis at Hamburg University. He is currently getting started on the MIX experiment with lots of plans for 2012. (01/2012)

The Lundbeck foundation has recently awarded a Junior Group Leader Fellowship to Jan Arlt to persue research on spinor gasses in optical lattices. The fellowships are intended for young researchers to establish or develop their own research groups in frontline basic- or applied research. (11/2011)

Lundbeck foundation

AU press release

Published in Science Express!

Interferometers with atomic ensembles constitute an integral part of modern precision metrology. However, these interferometers are fundamentally restricted by the shot noise limit, which can only be overcome by creating quantum entanglement among the atoms. We used spin dynamics in Bose-Einstein condensates to create large ensembles of up to 10⁴ pair-correlated atoms with an interferometric sensitivity -1.6 dB beyond the shot noise limit. Our proof-of-principle results point the way toward a new generation of atom interferometers. (10/2011)

Danish press release

Science DOI: 10.1126/science.1208798

The first MOT was realized in the new MIX laboratory on the 13.9.2011 only 10 working DAYS after moving the experiment from Hannover to Århus! The atom number looks good and we can now start setting up the atom transport and detection. (09/2011)

The MIX experiment has finally arrived in Århus and successfully moved into its new laboratory! The experiment was partially disassembled in Hannover and moved to Århus by truck. Only the vacuum system (including glass cells) remained in one piece and under vacuum. The delicate vacuum system remained intact which should allow us to rebuild the experiment very quickly! Have a look at more images from the move! (8/2010)

In this paper 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. We monitor the evolution of these wave packets in-situ and observe a reflection on a band gap. 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.  arXiv:1107.1643 (07/2011)

Published in PRL!

Optically trapped atoms are very importnat  for frequency measurements and quantum memories, but generally suffer from strong dephasing due to inhomogeneous density and light shifts. We have demonstrated a drastic increase of the coherence time to 21 s on the magnetic field insensitive clock transition of ⁸⁷Rb by applying the recently discovered spin self-rephasing mechanism. The presented frequency standard provide high stability in a potentially very compact setup. arXiv:1103.2283 and Phys. Rev. Lett. 106, 240801 (2011) (06/2011)

The first BEC was realized in our new laboratory on the 3.5.2011 roughly 5 months after making the last BEC in our old lab and moving the experiment! The number of atoms and their temeperature is looking good and we can now fine tune it! (05/2011)