Can Angular Oscillations Probe Superfluidity in Dipolar Supersolids?

Now published in PRL! 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.

The paper can be accessed here: PRL 129, 040403 and the preprint here: arXiv:2111.07768

Erbium goes Rydberg

The TREQS team has made first observations of Erbium Rydberg levels in a hot atomic beam. We have found more than 550 highly excited states, which could be assigned to well-behaving ns, nd, ng series thanks to our collaborations with theorists Francis Robicheaux and Prof. Chris Greene from Purdue University.
Our results show how the unique properties of Erbium effect the Rydberg series and provide a first step to Rydberg physics with many-electrons atoms. In collaboration with Prof. Francis Robicheaux and Prof. Chris Greene from Purdue University, we have performed Multi-channel Quantum Defect Theory (MQDT) to explain our results, and assign principal quantum numbers to the s and d series. Our results open the way for future applications of Rydberg states for quantum simulation using Erbium and exploiting its unique properties based on its open-shell structure.

Our work has been published in the Open-Access Journal Physical Review Research