Interference of fractionally charged quasiparticles in a graphene quantum Hall interferometer
ORAL
Abstract
Fabry-Pérot quantum Hall interferometers provide a direct means to measure the charge and exchange statistics of quasiparticles inherently present in quantum Hall states. In recent years, devices constructed out of GaAs/AlGaAs quantum wells have demonstrated this geometry's aptitude in measuring fractional exchange statistics in several abelian odd-denominator states. Alongside, several groups including our own have been working to develop similar devices in graphene van der Waals heterostructures. While offering exceptional tunability, these graphite-gated devices notably offer a high degree of screening and bulk-capacitive coupling, promoting the desired Aharonov-Bohm operating regime and enabling smaller functioning devices with increased oscillation coherence. While these advantages have enabled our group to observe inter-edge coupling effects in integer quantum Hall states (to be discussed in a separate talk from our group), here we will describe our progress towards observing fractional exchange statistics in graphene-based devices. Specifically, we report on observing clear Aharonov-Bohm oscillations when interfering the fractional edge in odd-denominator fillings while modulating the effective device area with electrostatic gating.
–
Presenters
-
James Ehrets
- Harvard University