Center for Ultracold Atoms and Quantum Gases, IExP and IQOQI, Innsbruck
Thomas Bland 
The American Physical Society’s high impact journal Physical Review X has chosen its favourite papers for its tenth anniversary. Among those chosen was the first observation of a dipolar supersolid from our group and the simultaneous observation at the University of Stuttgart.
Full article available here: PRX – Ten Years After
In a new joint theory-experimental collaboration, we investigate the extent that angular oscillations of a dipolar supersolid can tell us about the superfluidity of the system. Previous investigations of this been confined to linear droplet arrays.
Here, together with Prof. Luis Santos at the University of Hannover, we explore angular oscillations in systems with 2D structure, which in principle have greater sensitivity to superfluidity. Surprisingly, in both experiment and simulation, we find that the frequency of angular oscillations remains nearly unchanged even when the superfluidity of the system is altered dramatically. Indicating that angular oscillation measurements do not always provide a robust experimental probe of superfluidity with typical experimental protocols.
After several months of preparations and setting up our system, we have produced our first ultracold atomic cloud of erbium atoms in our new T-REQS lab. After initial slowing down in a Zeeman slower with a broad transition, we trap and cool 166Er atoms in a 5 beam magneto-optical trap operating on the narrow linewidth transition at 583nm. We trap up to 120 million atoms and cool them to ~15 microkelvin in a compressed MOT phase. This is a first step on our way to trapping ultracold erbium atoms in optical tweezers.
We present a first study of the influence of the dipole-dipole interaction on the total inter-species interaction in our erbium-dysprosium mixture. In collaboration with M. Modugno from the University of the Basque Country, we develop a model for our heteronuclear mixture, which describes qualitatively well our system and allows us to predict a lower and an upper bound for the inter-species scattering length. With this work, we make the first steps toward the study of the experimentally unexplored miscibility-immiscibility phase diagram and the realization of quantum droplets and supersolid states in heteronuclear dipolar mixtures.
This work is now published as the editors’ suggestion in Phys. Rev. A [paper] [arXiv]
Farewell to Matthew Norcia who after an incredible two years here is moving back to Boulder (US). We wish you all the best for your next scientific adventure!
