Erbium Scientific News

Category for scientific news of the Erbium group

Review of quantum simulations of non-standard Bose-Hubbard models

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The article “Recent progress on quantum simulations of non-standard Bose-Hubbard models” by Priv. Doz. Dr. Manfred Mark and collaborators has been accepted to Reports on Progress in Physics! The field of quantum simulation of Hubbard models has been growing extensively in the past decade. Here, we focus specifically on non-standard Bose-Hubbard models and discuss the progress made in both, the theoretical description and understanding as well as in the first experimental realizations.

Read the full article in Reports on Progress in Physics!

Optical Manipulation of Spin States in Ultracold Magnetic Atoms

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ImageWe present an all-optical method for deterministically controlling the spin composition of a quantum gas, based on a clock-like transition, and demonstrate that this transition can also be used to create spin-selective light shifts! 

The article has now been published in Physical Review Research, and the pre-print can be accessed here: arxiv.org/abs/2405.01499.

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

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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

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

A very excited dipolar quantum droplet

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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

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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

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