Description du sujet de thèse

The fractional quantum Hall effect is a physical phenomenon that hosts quasiparticles called anyons. These anyons have topological properties that make them interesting candidates for the development of topologically protected quantum processors. One type of anyons in particular, called non-abelian anyons, have been theorized in the ν=5/2 state of the fractional quantum Hall effect. The goal of this project is to experimentally evidence the properties of those states and determine their characteristics. During this project we will be interested in the study of magnetoplasmonic resonators based on two-dimensional electron gases in order to realize magnetoplasmonic interferometers. These interferometers will be used to evidence the non-trivial properties of abelian and nonabelian anyons present in the fractional quantum Hall effect. In order to perform these experiments, we will fabricate, using nano and micro-fabrication techniques, the necessary samples for this study. They will then be measured under high magnetic field at cryogenic temperatures within a dilution refrigerator. Experimentally, this project combines clean room fabrication, quantum transport and microwave engineering with the final goal of demonstrating interference effects resulting form the fractional phase of quasiparticles in the anyonic regime

Contexte de travail

This project will take place with the context of the MAHR ANR whose goals align with that of the PhD project. The hired student will work within the mesoscopic physics team at ENS. The research team has recently shown that it was possible to control electrostatically magnetoplasmonic cavities in the integer quantum Hall effect. We now aim at extending these results to the fractionnal quantum Hall effect and realise radiofrequency interferometers.