In December last year we moved our experiments from the MPIK in Heidelberg to the Physikalisches Institut, also in Heidelberg. In this new building, the rooms for our labs had just been finished before. We decided to keep the optics and vacuum chambers mounted on the tables for the move. This allowed us to start up our experiments quickly: As of now, one experiment is running as good as before the move, the other experiment is steadily getting there.

We just went on a short retreat with the Grimm group from Innsbruck. The two days at the monastry Maria Waldrast in the Austrian alps were full of interesting discussions, beautiful landscapes and nice hiking.

In front of the monastry Maria Waldrast

Walk in the afternoon

The people

The new BEC
Johanna Bohn recently finished her diploma thesis, which describes the setup of our new dipole trap and the molecular BEC we are able to create in this trap.
The thesis can be found here: diplomarbeit_johanna.pdf.

In our latest paper we make two distinguishable atoms behave as if they were fermions, and verify this by comparing them to two identical fermionic atoms. The paper has been selected as an editor's suggestion by PRL, and was highlighted by a Physics synopsis:
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.108.075303
2 distinguishable vs. 2 identical atoms

We sucessfully prepared a tunable quantum system consisting of one to ten fermions. We prepare such a system using ultracold Lithium atoms in a micrometer sized optical dipole trap. Due to Pauli's principle one quantum state in the trap is occupied with one atom per spin state (red and blue balls). By tilting the trap we can control the number of remaining quantum states and thus the number of particles.
Schematic preparation scheme of the tunable few-fermion system
The paper is published in the current issue of Science. The ArXiv version can be found here and there is also a press release (in German) by the University of Heidelberg.

The ultracold quantum gases group proudly present its new bubble chamber implemented at the Max-Planck Institute. Due to space constraints it has been temporarily placed inside Selim's office.

Experimental Setup

First Event

Philipp Simon recently handed in his diploma thesis, which further characterizes the new MOT and Zeeman slower and can be found here:

diplomarbeit_philipp.pdf.

We have associated an univeral three-body bound state, so called Efimov state, and measured its binding energy as a function of interaction strength with radio-frequency spectroscopy.
The paper has been published in the current issue of Science. The arxiv version can be found here.

Signal of the trimer association (red points) for different interaction strengths.

The new MOT
We recently finished the construction of a new magneto-optical trap (MOT). With loading rates of 3·10^8 and higher, it will serve as a fast and efficient precooling stage for future experiments. The background collision limited lifetime of atoms in the trap is approximately 23 minutes.

More details on the apparatus can be found in Martin Ries' diploma thesis, which was handed in recently. It is now available online: diplomarbeit_martin.pdf.