Link : https://univ-grenoble-alpes-fr.zoom.us/j/92146417296?pwd=NzlNeGRlbGpzaEJMbW94cEJVWGU1Zz09
Seminar room of Building A : the number of person is limited to 30
The presentation will be in english.
Electron interferometry with quantum Hall (QH) edge channels in semiconductor heterostructures can probe and harness the exchange statistics of anyonic excitations. However, the charging effects present in semiconductors have often obscured the Aharonov–Bohm interference in QH interferometers and make advanced charge-screening strategies necessary.
In this PhD thesis, we successfully fabricated encapsulated graphene heterostructures equipped with quantum point contacts in series that operate as quantum Hall Fabry-Pérot interferometers. We demonstrate that these devices display gate-tunable Aharonov-Bohm oscillations free of charging effect and in full agreement with theory. We investigate the quantum coherence of electron transport in these interferometers and the possibility to operate a coherent double Fabry-Pérot interferometer. We also investigate the possibility to make interference in the fractional quantum Hall regime and we unveil the existence of phase jumps in Aharonov-Bohm oscillations that resemble those interpreted as signature of anyonic statistics. Our work demonstrates that graphene devices offer a new platform to investigate the physics of quantum Hall Fabry-Pérot interferometers and open up new paths towards the probing of anyon physics emerging the fractional quantum Hall regime.