Our research activities concentrate on experiments in the field of ultra-cold atom gases. We employ them as platforms for studying quantum many-body issues at the frontier of condensed matter physics. Current work focuses on quantum magnetism and we aim at producing strongly-correlated states. our group is part of the Laboratoire de Physique des Lasers located at Université Sorbonne Paris Nord.
Contact : Martin Robert-de-Saint-Vincent (group leader, CNRS)
THE CHROMIUM BEC LAB:
In recent years, we performed various studies of dipolar effects in condensates made of spin-3 chromium atoms with a special interest into the properties of spinor quantum gases in bulk or in optical lattices. We take advantage of the remarkable properties of chromium atoms (high spin, large magnetic moment) to demonstrate new physical effects triggered by the interactions between dipoles inside the chromium Bose-Einstein condensates.Read more on the project here.
Contacts: Laurent Vernac (University Sorbonne Paris Nord), Lucas Lavoine, (University Sorbonne Paris Nord), Benjamin Pasquiou (CNRS), Bruno Laburthe-Tolra (CNRS)
THE STRONTIUM 87 LAB:
We designed the strontium experiment to study the quantum magnetism of large spin (9/2) fermionic particles, with an original SU(N) symmetry that reflects the invariance of interactions by any spin rotation. We reached Fermi degeneracy in spring 2019. Now, we are investigating the use of the narrow lines of strontium to manipulate and probe the spin degree of freedom of these atoms, exploiting the extraordinary degree of energy sensitivity afforded by metrology tools (in collaboration with the Metrology group of our lab). Next, we will apply these tools in optical lattices for the preparation and study of novel magnetic materials. Read more on the project here.
Contacts: Martin Robert-de-Saint-Vincent, Benjamin Pasquiou, Bruno Laburthe-Tolra (CNRS)
THE SUPERRADIANT LASER LAB:
Under controlled conditions, the collective emission of light by an ensemble of emitters leads to intriguing effects, such as the spontaneous emergence of entanglement and altered emission properties. We will make use of the collective phenomenon called superradiance to create a source of light with ultrastable frequency and a linewidth even below that of individual emitters. Using a beam of strontium atoms passing through an optical cavity, we aim at bringing this “superradiant laser” to the continuous regime, where it may be used as a novel type of atomic clock. Read more on the project here.
Contacts: Martin Robert-de-Saint-Vincent, Benjamin Pasquiou, Bruno Laburthe-Tolra (CNRS)
THE THEORETICAL LAB:
Contact: Paolo Pedri (University Sorbonne Paris Nord )
Recents news and results
New arrival: Cristian Serna
A new team member arrived: welcome to Cristian Serna, who is starting his M2 internship with the superradiant lab team.
New arrival: Fatima Rahmouni
A warm welcome to Fatima Rahmouni, the new postdoc of the chromium BEC lab! She is in charge of the big upgrade to v2.0 of the chromium experiment.
2025 – M2/PhD internship proposal on the chromium experiment
Trapping laser system for a dipolar quantum gases experiment
New arrival: Lily Marquié
Welcome to Lily Marquié, starting her PhD on the strontium apparatus!
2025 – PhD proposal on the Superradiant laser experiment
Continuous superradiant laser with a laser-cooled atomic beam
QuRIOUS doctoral network
We celebrate the success of the Qurious doctoral training network: we now have partners all across Europe, with whom to develop a new generation of atomic clocks and train 15 PhDs. More informations on the network at https://www.quriousclocks.eu/ and on thesis opportunity in our group here.
Spin manipulation in a Fermi degenerate gas of 87Sr: implementation of a new laser solution in the experimental setup
Master 2 internship (4 months) / Download report
The atomic beam crosses the cavity mode.
The preparation of the atoms in the excited state, before they enter the cavity, seems to work. Efforts are under way to laser-cool further the atomic velocity distribution, in directions transverse to the atomic beam flow.
All news and results can be found here.
Fundings:
Our activities are funded by the European Research Commission (QuantERA ERA-NET Cofund 2019), Agence Nationale de la Recherche (PRC Technologies Quantiques 2023, 2021, and 2019, Tremplin-ERC 2017), Region Île-de-France through the Institut FRancilien des Atomes Froids and the Domaines d’Intérêts Majeurs QUANTIP, SIRTEQ, Nano’K, IFCPAR, and Labex FIRST-TF.