  Devices made from graphene encapsulated in hexagonal boron-nitride exhibit
pronounced negative bend resistance and an anomalous Hall effect, which are a
direct consequence of room-temperature ballistic transport on a micrometer
scale for a wide range of carrier concentrations. The encapsulation makes
graphene practically insusceptible to the ambient atmosphere and,
simultaneously, allows the use of boron nitride as an ultrathin top gate
dielectric.
