Aurore Alice Young | Searcharxiv

arXiv2026

Spin-exchange interactions between circular Rydberg atoms over long times

Arrays of neutral atoms excited to Rydberg levels have emerged as one of the most promising platforms for quantum computation and simulation. With the hope to outperform classical devices, the number of atoms has been increased by orders of magnitude. However, the interaction time, i.e., the maximum accumulated time during which an atom interacts with its neighbours, has been limited to a few microseconds only. This restrains the number of gates per atom or prevents the simulation of long-time dynamics of quantum many-body systems. Here, we observe the spin-exchange interaction between two spin 1/2s encoded in laser-trapped circular Rydberg atoms over more than $60μs$ and 40 spin-oscillation periods, improving the state of the art by an order of magnitude. These unprecedented timescales allow us to record for weak atomic trapping a collapse and revival of the spin-exchange oscillation contrast induced by spin-motion coupling. Our results constitute the first observation of this coupling with laser-trapped Rydberg atoms. To counteract its detrimental effect for quantum simulation, we demonstrate a novel dynamical decoupling method that prevents the collapse of the spin oscillations. This method exploits the advantages of our recently developed hybrid platform that enables the measurement and the optical manipulation of long-lived circular Rydberg atoms with auxiliary Rydberg atoms. This work opens a direct route to long-duration quantum simulation of strongly-interacting many-body systems.

physics.atom-ph↗

arXiv2025

Non-destructive optical read-out and manipulation of circular Rydberg atoms

Among the thriving quantum computation and quantum simulation platforms based on arrays of Rydberg atoms, those using circular Rydberg atoms are particularly promising. These atoms uniquely combine the strong dipole-dipole interactions typical of Rydberg states with long lifetimes. However, low-angular-momentum ($\ell$) laser-accessible Rydberg levels have been so far mostly used, because circular Rydberg atoms have no optical transitions, hindering their individual detection and manipulation. We remove this limitation with a hybrid platform, combining an array of logical laser-trapped circular Rydberg atoms of rubidium with an auxiliary array of Rb ancilla atoms transiently excited to a low-$\ell$ Rydberg level. We perform a quantum non-demolition detection of the logical qubit with the ancilla, through the blockade of the ancilla optical excitation induced by a Förster resonance. Conversely, we locally manipulate the logical qubit through the excitation of the ancilla. This dual-Rydberg platform is highly promising for quantum computation and simulation. It adds to the circular-atom toolbox the mid-circuit measurements, essential for error correction. More strikingly, it gives access to time correlations in long-term quantum simulations, uniquely accessible to circular Rydberg atoms.

physics.atom-ph↗