STAGE Superconducting resonators to probe diverging dielectric constants

Date de mise à jour de l’offre

ESPCI PARIS :

Ecole d’ingénieurs de la Ville de Paris fondée en 1882, l’École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris) est un endroit unique, au cœur de la Montagne Sainte-Geneviève dans le 5e arrondissement. Elle se démarque par sa formation scientifique de haut niveau, interdisciplinaire, fortement adossée à une recherche d’excellence, alliant science fondamentale et ouverture vers les applications et l’innovation. Elle est la première école d’ingénieurs française au classement de Shanghai (classe 300/400). Distinguée par 6 prix Nobel, elle allie recherche d’excellence (1 publication par jour), innovation (1 brevet par semaine, 3 start-up par an) et formation interdisciplinaire par la recherche. Elle accueille 400 élèves ingénieurs, 600 chercheurs dans 11 unités de recherche et environ 100 agents de support de la recherche et de l’enseignement.

Description de la mission

Modern electronics is based on nanometric size Field Effect Transistors, whose conductance is modulated by mean of a gate voltage, through a capacitor. The race for miniaturizing micro-processors even further depends on the ability of making very small capacitors with high capacitance, thanks to high dielectric constant materials. On another hand, current developments in electronics and photonics require innovative ways to produce tunable LC circuits in order to control electromagnetic waves at sub-wavelength scales: this is the field of the so called "meta-materials".
For this project, we propose an original approach to realize tunable capacitors with large capacitance by taking advantage of the divergence of the dielectric constant near the disorder-induced Anderson metal-to-insulator transition. Indeed, metals (and superconductors) can turn into insulators when the atomic disorder is increased, and reaches a critical value for which electronic wave-functions are localized. In the vicinity of this Quantum Critical Point, numerous physical quantities diverge, and so does the dielectric constant.
We will probe this divergence in the microwave regime by using YBa2Cu3O7 (YBCO) thin films. This material is known to be a High-Tc superconductor (Tc = 90 K), whose disorder induced transition to the insulating state can be promoted by high energy ion irradiation. Using nano-fabrication techniques, we will make half-wavelength superconducting LC resonators with high quality factors, whose resonance frequency will be controlled by ion-irradiated YBCO capacitors [Fig.1a]. We will make samples with capacitors fabricated at different ion-irradiation doses - corresponding to different amounts of disorder - to progressively approach the Anderson transition. The resonance frequency will be determined from microwaves transmission measurements at low temperature (T = 4-90 K) in a cryogen-free cryostat.
The objectives of these experiments are two fold. On the basic science side, we will get a better understanding of the dynamical properties of the electrons near a Quantum Critical Point. On the applied side, we will use these results to engineer tunable meta-materials for high frequency operation in collaboration with a Singaporean team, single photon detectors and THz mixers. The extension of similar studies to a large variety of devices for electronic and photonic applications is foreseen.

Profil recherché

Ingénieur

Niveau de qualification requis

Bac + 4/5 et +
  • Employeur
    ESPCI PARIS
  • 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.espci.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 2 mois et jusqu'à 4 mois
  • Le stage est-il rémunéré ?
    Oui
  • Niveau de qualification requis

    Bac + 4/5 et +
  • Lieu du stage
    10 Rue Vauquelin
    75005 PARIS 5E ARRONDISSEMENT
  • Accès et transports
    Metro et Bus