Manfred Mark

A Thouless pump with dipolar interactions

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Thouless pumping represents a powerful concept to probe quantized topological invariants in quantum systems. We explore this mechanism in a generalized Rice-Mele Fermi-Hubbard model characterized by the presence of competing onsite and intersite interactions. While large on-site repulsion leads to a breakdown of quantized pumping , sufficiently large intersite interactions allow for an interaction-induced recovery of Thouless pumps. The stable topological transport at large interactions is connected to the presence of a spontaneous bond-order-wave in the ground-state phase diagram of the model. We also discuss a concrete experimental setup based on ultracold magnetic atoms in an optical lattice.

The pre-print can be accessed here: arXiv

A ship-in-a-bottle quantum gas microscope

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Quantum gas microscopes are versatile and powerful tools to investigate lattice systems down to the single atom level. Here we present a quantum gas microscopy setup for experiments with highly magnetic atoms of the lanthanoid elements erbium and dysprosium. Our setup features a quartz glass cell, enclosed by a compact multi-shell ferromagnetic shield. Inside, a non-magnetic, non-conducting, large-working-distance, high-numerical-aperture, in-vacuum microscope objective will enable single-site imaging of our strongly dipolar atomic mixture.

See the pre-print here: arXiv:2306.05404

LFUI Guest Professorship granted

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Luca Barbiero
Politecnico di Torino, Italy

Our group is very happy to announce that Dr. Luca Barbiero, currently Asssistent Professor at Politecnico di Torino, will visit us for a LFUI Guest Professorship for two months during October and November 2023. During his stay we will together work on new ideas on how to use our experimental dipolar platforms for the quantum simulation of Bose- and Fermi-Hubbard models with strong dipolar interactions. He will also give a special lecture on equilibrium and out-of-equilibrium properties of dipolar lattice systems to interested Master- and PhD-students.

Can Angular Oscillations Probe Superfluidity in Dipolar Supersolids?

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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

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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

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