Quantum Simulation with Long-Range-Interacting Dysprosium and Erbium: from Microscopy to Rydberg Tweezers

Project Information

DyMETEr

Grant agreement ID: 101054500

DOI

10.3030/101054500

EC signature date 20 June 2022

Start date 1 October 2022

End date 31 July 2028

Funded under

• European Research Council (ERC)

Total cost

€ 2 498 160,00

EU contribution

€ 2 498 160,00

Coordinated by

UNIVERSITAET INNSBRUCK
Austria

Periodic Reporting for period 1 - DyMETEr (Quantum Simulation with Long-Range-Interacting Dysprosium and Erbium: from Microscopy to Rydberg Tweezers)

Reporting period: 2022-10-01 to 2025-03-31

Summary of the context and overall objectives of the project

With the first realization of an atomic Bose-Einstein condensate (BEC) passing its 25th anniversary, the field of ultracold atoms is rapidly progressing towards physical scenarios that go far beyond the scope originally envisioned. Recently, two emerging platforms sparked enthusiasm as they promise novel enhanced opportunities for quantum science: dipolar quantum gases with magnetic lanthanides and tweezer arrays of alkaline-earth Rydberg atoms. These two systems provide complementary approaches to the study of the fascinating phases and phenomena of long-range interacting quantum matter. The interplay of long- and short-range interactions already showed dramatic consequences with novel, fascinating, and sometimes unexpected few- and many-body phenomena, such as chaotic scattering, Fermi surface deformation, roton excitation modes, liquid-like self-bound droplets, and the long-sought supersolid states of matter.
DyMETEr will create novel quantum platforms of enhanced capability by using ultracold lanthanides, specifically Erbium and Dysprosium, as building-block to unprecedentedly access many-body phases of dipolar mixtures, realize dipolar quantum gas microscopy, and implement multi-valence-electron Rydberg quantum simulators. More specifically, the main project objectives of DyMETEr are the preparation and study of many-body phases of matter in dipolar quantum mixtures, the realization of a dipolar mixture quantum gas microscope to unveil exotic new quantum phases of dipoles in solid-state like crystal structures, and the demonstration of a quantum simulator using multi-valence-electron Rydberg atoms in reconfigurable Tweezer arrays. These objectives are at the frontiers of research that a few years ago we could only dream of but that today define the three goals of DyMETEr.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Within our first goal - dipolar quantum mixtures and bulk phases of dipolar quantum gases - we have accomplished great progress in the further understanding of those systems, both in theory and experiment. Together with theory collaborators our team has investigated the compressibility and speeds of sound across the supersolid phase transition and excitations of binary dipolar supersolids. We also established a collaboration with a team of astrophysicists from the Laboratori Nazionali del Gran Sasso where we found a strong analogy between rotating supersolids and neutron stars, indicating a possible explanation of the so-called “glitches” observed in actual measurements from neutron stars. Our experimental work succeeded in observing the so-called “Anti-roton” effect, a manifestation of the increased rigidity of a quantum droplet against excitations. We also realized for the first-time coherent spin control of bosonic erbium, pathing the way to investigate dipolar spin mixtures. Finally, we observed the presence of vortices in spinning dipolar supersolids and found striking differences in the vortex creation compared to unstructured superfluids.
For our second objective - the investigation of lattice physics with long-range interacting dipoles - we already successfully implemented a new science chamber with an in-vacuum high-resolution objective in the experimental setup, that will allow us to perform ultrafast quantum gas microscopy. The current work consists of transporting the ultracold atoms into this science chamber and implementing the lattice structure for first studies of the dipolar gas in the quantum gas microscope. In our second experimental apparatus we demonstrated full control over the spin manifold of bosonic erbium atoms using an ultranarrow optical transition. This new experimental method overcomes current limitations due to the absence of nuclear spin and allows us high-fidelity state preparation as well as the control and suppression of spin-exchange processes.
Our third goal - realizing a reconfigurable single-atom tweezer array with erbium for quantum simulation – has reached an important first milestone. We successfully finished the main experimental setup and were able to prepare and detect single erbium atoms in a tweezer array. We also demonstrated our ability to free-space ultrafast image erbium atoms, which allowed us to measure and discriminate the number of atoms in each tweezer and to study the dynamics during light-assisted collisions. Our next steps involve the spectroscopy and excitation of Rydberg states as well as investigating the specific properties and optical manipulation possibilities.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The results of our collaboration with a team of astrophysicists – the strong analogy between rotating dipolar supersolids and the inner crust of rotating neutron stars – opens the door for future quantum simulations of the whole neutron star from the core to the crust in earth-based experiments, a rare opportunity in the field of astrophysics. Our most recent experimental results showing the presence of vortices in a rotating supersolid are already a first step towards this very promising and exciting scenario.
The trapping and imaging of single erbium atoms in an optical tweezer array is an important milestone on the way to realize a quantum simulator based on multi-electron Rydberg atoms. It shows that – despite the rather complex energy spectrum of lanthanides – it is possible to trap, cool and image them in those tight tweezer traps and at the same time offers additional tuning knobs as the demonstrated anisotropic polarizability.