Clément Sayrin
LightNews LightNews
banner
clementsayrin.bsky.social
Clément Sayrin
@clementsayrin.bsky.social
210 followers 310 following 27 posts
Associate professor @sorbonne-universite.fr, Quantum Physicists at LKB, traps circular Rydberg atoms
Posts Replies Media Videos
clementsayrin.bsky.social
In this picture, the ancilla circular atoms stay in n=52 (small blue torus) if a nearby ancilla is in 45S (large green sphere) but it is excited to n=54 (large red torus) if the ancillae are in their ground state (small red sphere). (13/14)
September 30, 2025 at 9:27 PM
clementsayrin.bsky.social
If we try and optically excite the ancilla to 45S, the process is impervious to the presence of a circular atom with n=52. However, if the circular atom is in n=54, the strong interaction splits the excitation line and blocks the excitation, in a usual Rydberg blockade mechanism. (10/14)
Population in the ground state after the optical excitation of the ancilla to 45S, as a function of the frequency of the excitation laser. The blue squares are measured with a circular atom in n=52, the red spheres with n=54. A low probability indicates a successful excitation
September 30, 2025 at 9:27 PM
clementsayrin.bsky.social
In this work, we make circular Rydberg atoms (blue torus in the picture) interact with other atoms initially in their ground state (red spheres) and excited to low-angular-momentum Rydberg levels. All atoms are laser trapped in the experiment. (8/14)
Three atoms on a line: a red sphere (ground state), a blue torus (circular Rydberg state), and another red sphere. The ground state atoms are trapped in focused Gaussian beam (red beam) and and the circular atom in a bottle beam (blue beam).
September 30, 2025 at 9:27 PM
clementsayrin.bsky.social
They can also be laser trapped in so-called optical bottle beams, that present a local minimum of intensity. (5/14)
A circular Rydberg atom (blue torus) inside an optical bottle beam (blue beam with an intensity minimum at the place of the atom).
September 30, 2025 at 9:27 PM
clementsayrin.bsky.social
I am quite happy to share our latest work from the #Rydberg Atoms team of @lkblab.bsky.social, that just appeared on arXiv, by Yohann Machu and all the Rb team @college-de-france.fr @psl-univ.bsky.social @normalesup.bsky.social @cnrs.fr @sorbonne-universite.fr (1/14)

arxiv.org/abs/2509.24691
Four ensembles of atoms arranged on a square. Within every ensemble, there are three atoms. On the two left ensembles, the central atom is depicted with a yellow torus (circular Rydberg level) and the two outer ones with a red sphere (ground state). In the two left ensembles, the central atom is depicted by a small blue torus (circular level), the left atom as a large green sphere (other Rydberg level) and the right atom as a red sphere. All red-sphere atoms are illuminated by a red beam that represents a laser trap.
September 30, 2025 at 9:27 PM
clementsayrin.bsky.social
Vous pourrez y croiser des objets ou des instantanés échappés de nos laboratoires et même une revisite de réseaux d’atomes piégés en pinces optiques.
Une vue artistique d’un réseau d’atomes observés par fluorescence, représentés par une mosaïque de photographies d’une femme. Certaines des photos s’allument transitoirement.
April 9, 2025 at 7:03 PM
clementsayrin.bsky.social
Dites @francetv.bsky.social #france2, on essaie d’apprendre à nos étudiants le concept de « nombre de chiffres significatifs ». C’est bien de fournir des exemples de ce qu’il ne faut pas faire mais quand même… une hausse de température estimée à 10 nano degrés près, vraiment ?
Extrait du journal météo climat de France2. Le présentateur montre la hausse de température annoncée due à l’influence humaine, de 1,35808944°C.
March 28, 2025 at 8:35 PM
clementsayrin.bsky.social
Twenty years after my master internship (ouch, I feel old… 👨‍🦳), it was great to be back in Harvard and @mitofficial.bsky.social to visit the wonderful labs of the CUA and talk there about our circular #Rydberg atoms!
Night view from building in Harvard university. Photo of Ray and Maria Stat center in MIT, Boston
November 15, 2024 at 1:00 AM
clementsayrin.bsky.social
News from Kastler Brossel Laboratory! We have measured the dipole-dipole interaction between two circular #Rydberg atoms trapped in optical bottle beams.

Check out our now work on the arXiv: arxiv.org/abs/2407.04109

@collegedefrance.bsky.social @cnrs.bsky.social ENS-PSL Univ. Sorbonne Univ.
Two circular Rydberg atoms are trapped in a pair of optical bottle beams. They interact through dipole-dipole interaction. The distance d between the atoms and the angle theta between the interatomic axis and the quantization axis are represented.
July 8, 2024 at 4:50 AM