STAGE Momentum correlations in the critical regime of the Mott transition

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Laboratoire Charles Fabry :

Le laboratoire Charles Fabry est une Unité Mixte de Recherche entre l'Institut d'Optique Graduate School et le CNRS et en partenariat avec l'Université Paris-Sud et l'Université Paris-Saclay. Organisé en huit groupes de recherche aux thèmes bien définis, iI est le pilier historique de la recherche au sein de l'Institut d'Optique Graduate School. La recherche du laboratoire couvre un large spectre de l'optique-photonique et de ses applications. Le laboratoire Charles Fabry est de ce fait un laboratoire d'interface entre deux instituts du CNRS. Principalement rattaché à l'Institut de Physique, il est également rattaché à l'Institut des Sciences de l'Ingénierie et des Systèmes. Le laboratoire est constitué d'environ 120 personnes dont 19 chercheurs CNRS, 24 enseignants-chercheurs de l'Institut d'Optique Graduate School ou de Paris-Sud et de 21 personnels de soutien à la recherche. Les doctorants, postdoctorants et visiteurs représentent plus de la moitié des effectifs du laboratoire. Cel

Description de la mission

Many-body quantum states and dynamics can in principle be characterized by measuring all correlation functions
between individual quantum particles. In practice, accessing correlations at the single particle level turns out difficult
and only a few platforms ions, superconducting qbits or quantum gases offer this possibility. In our lab, we are
pursuing this line of research with an original approach consisting in measuring correlations between individual atoms
in the momentum (velocity) space. To do so, we have built a dedicated apparatus that produces Bose-Einstein
condensates of metastable Helium atoms . Our detection method is based on the special properties of metastable
Helium atoms: the large internal energy (20 eV) stored in the metastable state allows for reconstructing the threedimensional
momentum coordinates of individual atoms.
By loading atoms into a 3D optical lattice, a standing light wave along the 3 directions of space, one creates a periodic
potential for the atoms and, effectively realizes a crystal of light for the quantum gas. This is the starting point to
implement a series of many-body Hamiltonians inspired by solid-state physics. Doing so, we have investigated the
Bose-Hubbard phase diagram in momentum space, from the superfluid-to-normal phase transition to the quantum
phase transition towards the Mott insulator [in preparation]. Using our quite unique probe we have recently studied
correlations between two and three individual atoms in the Mott insulator state .
During the internship, the candidate will investigate the critical regime of the Mott transition, where multi-particle
correlations are expected in the momentum space but without observation reported so far. This aim touches upon
fascinating questions one may ask about the realization of a quantum phase transition in a quantum gas experiment:
what is the role of the inhomogeneous trap, the finite size of the system and the non-zero temperature on the properties
of the critical regime? is it possible to extract information on multi-particle entanglement from the measurement of
many-body correlations?
The apparatus is currently running with the bosonic species Helium-4 but we have started building the lasers to cool the
fermionic species Helium-3. Being able to load fermions into the 3D lattice will open novel and fascinating scientific
perspectives. This new direction will be at the center of a PhD thesis following the internship.

Profil recherché

Master

Niveau de qualification requis

Bac + 4/5 et +
  • Employeur
    Laboratoire Charles Fabry
  • Secteur d’activité de la structure
    Enseignement - Formation - Recherche
  • Effectif de la structure
    De 51 à 250 salariés
  • Site internet de la structure
    https://www.lcf.institutoptique.fr
  • Type de stage ou contrat
    Stage pour lycéens et étudiants en formation initiale
  • Date prévisionnelle de démarrage
  • Durée du stage ou contrat
    Plus de 4 mois et jusqu'à 6 mois
  • Le stage est-il rémunéré ?
    Oui
  • Niveau de qualification requis

    Bac + 4/5 et +
  • Lieu du stage
    Institut d’Optique Graduate School, 2 avenue Augustin Fresnel,
    91127 PALAISEAU
  • Accès et transports
    RER et bus