Time-dependent transport in Graphene Mach-Zender Interferometers

Abstract: Graphene nanoribbons provide an ideal platform for electronic interferometry in the Integer Quantum Hall regime. Here, we solve the time-dependent four-component Schroedinger equation for single carriers in graphene and expose several dynamical effects of the carrier localization on their transport characteristics in pn junctions. We simulate two kinds of Mach-Zender Interferometers (MZI). The first is based on Quantum Point Contacts and is similar to traditional GaAs/AlGaAs interferometers. As expected, we observe Aharonov-Bohm oscillations and phase averaging. The second is based on Valley Beam Splitters, where we observe unexpected phenomena due to the intersection of the Edge Channels that constitute the MZI. Our results provide further insights into the behavior of graphene interferometers. Additionally, they highlight the operative regime of such nanodevices for feasible single-particle implementations.