Phase space analysis of quantum transport in graphene
Prominent among the many fascinating properties of graphene are its surprising electronic transport characteristics which are commonly studied theoretically and numerically within the Landauer-Buttiker formalism. Here a device is characterized by its scattering properties to and from reservoirs connected by perfect semi-infinite leads, and transport quantities are derived from the scattering matrix. In many respects, however, the device becomes a `black box' as one only analyses what goes in and out. Here we use the Husimi function as a complementary tool for understanding transport in graphene nanodevices. It is a phase space representation of the scattering wavefunctions that allows to link the scattering matrix to a more semiclassical and intuitive description and gain additional insight in to the transport process. In this article we demonstrate the benefits of the Husimi approach by analysing \emph{Klein tunneling} and \emph{intervalley scattering} in two simple graphene nanostructures.