Erbium Scientific News

Category for scientific news of the Erbium group

Der Suprafestkörper: a popular science article on the dipolar supersolid!

by

imageIf you have been searching for a high-level overview of the dipolar supersolid phase, look no further than this open access article by Prof. Francesca Ferlaino and Dr. Manfred Mark! Newly published in the journal “Physik in unserer Zeit”, this German language primer lays out the historical background, newly discovered properties and open questions which remain about this paradoxical quantum phase. See the full article below:

Ferlaino, F. and Mark, M.J. (2024), Der Suprafestkörper. Phys. Unserer Zeit. https://doi.org/10.1002/piuz.202301692

A Thouless pump with dipolar interactions

by

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 article can be found here: Quantum, the pre-print can be accessed here: arXiv

A very excited dipolar quantum droplet

by

Now published in PRL!  Together with collaborators from the University of Otago, we present the the excitation spectrum of Erbium at the crossover from a Bose-Einstein condensate to a trapped macrodroplet. The measurements coincide well with the predictions and confirm the peculiar features of this spectrum: a strong upward shift in energy at low momentum and the appearance of multiple excitation branches at higher momentum. It turns out that these features can be explained by the tendency of the excitations to avoid the central dense part of the droplet and by becoming more like ripples moving over the surface of a droplet!

Read it in Physical Review Letters, Phys. Rev. Lett. 132, 103401,  and see the pre-print here: arXiv:2308.00003.

A Thouless pump with dipolar interactions

by

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 very excited dipolar quantum droplet

by

Now published in PRL!  Together with collaborators from the University of Otago, we present the the excitation spectrum of Erbium at the crossover from a Bose-Einstein condensate to a trapped macrodroplet. The measurements coincide well with the predictions and confirm the peculiar features of this spectrum: a strong upward shift in energy at low momentum and the appearance of multiple excitation branches at higher momentum. It turns out that these features can be explained by the tendency of the excitations to avoid the central dense part of the droplet and by becoming more like ripples moving over the surface of a droplet!

Read it in Physical Review Letters, Phys. Rev. Lett. 132, 103401,  and see the pre-print here: arXiv:2308.00003.

Review of recent experiments with dipolar gases

by

The last 15 years has seen tremendous experimental progress for the manipulation and control of ultracold atoms with sizeable dipole-dipole interactions. In this review, together with other group leaders who first condensed dysprosium and chromium, we review the discoveries made so far, and lay out the future perspectives for this exciting field!

The paper can be found here: Dipolar physics: a review of experiments with magnetic quantum gases – IOPscience

+ More