Cavité diélectrique à volume de mode fortement sub-longeur d'onde pour électrodynamique quantique en cavité avec nano-émetteurs

Deep sub-wavelength dielectric cavities for cavity quantum electrodynamics with nano-emitters.

• Auteur / Autrice : Federico Rapisarda
• Direction : Christophe Voisin
• Type : Projet de thèse
• Discipline(s) : Physique
• Date : Inscription en doctorat le 01/09/2021
• Etablissement(s) : Université Paris sciences et lettres
• Ecole(s) doctorale(s) : Physique en Ile de France
• Partenaire(s) de recherche : Laboratoire : Laboratoire de Physique de l'École normale supérieure
• Partenaire(s) de recherche : établissement opérateur d'inscription : Ecole normale supérieure

Mots clés

Mots clés libres

Information quantique

Communication quantique

Interaction lumière-matière

Nano-structures

Quantum information

Quantum communication

Light-matter interaction

Nano-structures

Résumé

Le travail est essentiellement à caractère expérimental et de modélisation. Il concerne le développement, la fabrication et la caractérisation de nano-antennes diélectriques destinées à confiner le champ électromagnétique sur des volumes largement inférieurs à la limite de diffraction. L'objectif est d'y coupler des nano-émetteurs individuels (Nanotubes de carbone, graphene quantum dots,…) dans le but d'exacerber les effets d'electro-dynamique quantique en cavité pour générer des états non classiques du chanp électromagnétique.

Coupling nano-emitters to optical micro-cavities has a wide range of applications: among them the possibility to modify “natural” properties such as spontaneous emission (the so-called Purcell effect: acceleration of the spontaneous decay rate and efficient funneling of photons into a single optical mode, with applications for quantum telecommunication). It can also be used to generate coherent superposition of light and matter states (polaritons), which open the door to many advanced photonic functionalities, such as the few photon non-linearity, quantum gates... The strength of light-matter coupling depends crucially on the ratio Q/V where V is the cavity mode volume and Q is the lowest quality factor of the system. Two main routes are presently pursued to maximizes this figure of merit : the plasmonic route, where Q is limited by Ohmic losses in the metal, but where the mode volume can be strongly sub-wavelength and the dielectric resonator route, that can have very high Q but where the mode volume is limited by diffraction. Here, we propose to get the best of both approaches by designing and fabricating modified dielectric cavities (hence with high Q) with deep sub-wavelength volume. These cavities will be used for coupling solid state nano-emitters such as carbon nanotubes, graphene quantum dots, perovskite quantum dots, 2D transition metal dichalcogenides... By using the discontinuities of the electric field at interfaces and using a specific antenna geometry, it is possible to create an anomaly in the E field leading to an extremely small effective mode volume, with virtually no lower limit. The cavity that we propose to develop here can be decomposed in two part: the outer part will be a fibered cavity which gives a high Q factor whereas the inner part will be a dielectric nano-antenna (with a bow tie shape) fabricated on the tip on the fiber, leading to the sub-wavelength volume.