STAGE Probing valley Hall currents in graphene

Date de mise à jour de l’offre

Centre de Nanosciences et Nanotechnologies C2N UMR 9001 :

Le Centre de nanosciences et de nanotechnologies - C2N (CNRS/Université Paris-Sud - Université Paris-Saclay), a été créé le 1er juin 2016 du regroupement de deux laboratoires franciliens leaders dans leur domaine : le Laboratoire de photonique et de nanostructures (CNRS) et l'Institut d'électronique fondamentale (CNRS/Université Paris-Sud). En 2018, les équipes s’installent dans un nouveau bâtiment au cœur du Campus Paris-Saclay. Le collège de direction du Centre de Nanosciences et de Nanotechnologies est composée du directeur, Giancarlo Faini, des quatre directeurs adjoints Laurent Vivien, Dafiné Ravelosona, Pierre-Yves Joubert et Jean-Christophe Harmand, ainsi que de la secrétaire générale Vanessa Tocut.

Description de la mission

The first isolation of graphene, one atom thick layer of carbon atoms arrange in hexagons, in 2005
attracted a lot of attention given its remarkable characteristics: high carriers mobility, ambipolar
behavior, great mechanical strength. Not long after this, other 2D layered materials were found to
have also remarkable characteristics and host a large number of phenomena of condensed matter
physics. A great technological achievement of our days is the stack of these 2D layers to form van
der Waals (vdW) heterostructures [Nat. Nanotech 5, 722] and therefore combine the properties of
each material to design materials with new properties [Nature 499, 419].
Contrary to conventional 2D materials, grown by molecular beam epitaxy, the layered vdW
structures can be make of any combination of 2D materials, given that there are not restrictions of
lattice parameter. Other degree of freedom of these heterostructures is the relative angular
alignment between its layers, which can dramatically alter its fundamental properties. A remarkable
example of this, predicted for certain vdW heterostructures, is the emergence of phases of matter
where charge carriers flow without dissipation. In heterostructures of graphene crystallographically
aligned with boron nitride (insulator isomorph to graphene), such a phase has been predicted.
However, due to the scarcity of experimental tools to control the layer alignment the observations
available remain inconclusive [Science 346, 448; Science adv. 4, eaaq0194].
In this experimental internship (with possibility to be extended to a PhD thesis), we propose to use
a new technique to control the angular alignment between layers in a vdW heterostructure [Science
361, 690] to investigate the generation and control of electrical signals related to this phases of
matter in graphene. The successful candidates will participate actively in sample fabrication
(assembly of vdW heterostructures, angular control of layers using an AFM, e-beam lithography)
and electronic transport measurements at low temperatures. Experience in micro and nano
fabrication process is not required since the students will have the necessary training at the lab.

Profil recherché

M2

Niveau de qualification requis

Bac + 4/5 et +
  • Employeur
    Centre de Nanosciences et Nanotechnologies C2N UMR 9001
  • Secteur d’activité de la structure
    Enseignement - Formation - Recherche
  • Effectif de la structure
    Plus de 250 salariés
  • Site internet de la structure
    https://www.c2n.universite-paris-saclay.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
    C2N Palaiseau –Avenue de la vauve, 91120 Palaiseau
    Avenue de la Vauve
    91120 PALAISEAU
  • Accès et transports
    Rer B massy palaiseau puis bus