TOpological many-body states with ultracold RYDberg atoms

Informations projet

TORYD

N° de convention de subvention: 863880

DOI

10.3030/863880

Date de signature de la CE 19 Decembre 2019

Date de début 1 Septembre 2020

Date de fin 31 Août 2026

Financé au titre de

• EXCELLENT SCIENCE - European Research Council (ERC)

Coût total

€ 1 900 000,00

Contribution de l’UE

€ 1 900 000,00

Coordonné par

SORBONNE UNIVERSITE
France

Periodic Reporting for period 3 - TORYD (TOpological many-body states with ultracold RYDberg atoms)

Période du rapport: 2023-09-01 au 2025-02-28

Résumé du contexte et des objectifs généraux du projet

The overall objective of the project is to explore the dynamics, especially quantum transport, of a many-body quantum system. A specific focus is to develop new tools to go beyond the most commonly explored weakly-interacting regime. The main challenge of this project is to setup a platform based on low-dimensional gases excited to Rydberg states. This important goal will provide a new perspective on the field of quantum simulation.
In more details, we aim at trapping and manipulating ultracold gases of bosons in arbitrary-shaped potentials and then realize two-dimensional, one-dimensional or fully motionally frozen gases. These gases will be excited to a Rydberg state enabling strong interaction between particles. With this tool we expect to observe new many-body topological phases of matter.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

At mid-term of the project, we have successfully developed a new experimental platform allowing us to generate arrays of mesoscopic Bose gases. These gases contains atoms whose motion is fully frozen, a favorable situation to explore the physics of Rydberg superatoms. Moreover, we have shown single-photon excitation of these atoms to Rydberg states thanks to a dedicated UV laser. These two experimental developments represent two key milestones of the project.
In parallel, we also proposed and experimentally confirmed a method to create low dimensional gases of arbitrary density and spin profiles, a central result to explore quantum transport in low-dimensional gases. This new tool have been used to investigate the behaviur of the superfluid fraction of a Bose-Einstein condensate when submitted to a periodic potential. These transport studies enabled us to clarify and experimentally confirm the relationship between the density modulation of a condensate and his superfluid character.
Finally, we also studied the interaction between a condensate and weakly-bound dimers made of the same atoms as the one of the condensate. This may open interesting perspectives on the control of atomic interactions in a Bose gases.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

Thanks the demonstration of our ability to engineer highly tunable quantum gases and to Rydberg-excite them with a UV laser in the first half of the project, we will now focus on realizing yet unexplored many-body quantum phases. We will start by realizing independent super-atoms, corresponding to a situation where a single Rydberg excitation is shared by all atoms of a mesoscopic cloud. We will then explore the interaction of two neighbouring clouds and then generalize the problem to arrays of clouds. This will allow us to realize topological many-body states of great interest for quantum simulation. In parallel, we will explore Rydberg-dressing protocols to make bulk gases entering the strongly interacting regime. This will enable the study of many-body quantum transport.