  This manuscript deals with time flow in ballistic graphene devices. It is
commonly believed that in the ballistic regime the traversal time of carriers
in gated graphene at normal incidence is just the ratio of the length of the
device and the Fermi velocity. However, we show that the traversal time is much
slower if the influence of metallic contacts on graphene is considered. Even
the transmission at normal incidence becomes smaller than 1, contradicting yet
another common belief. These unexpected effects are due to the transformation
of Schrodinger electrons in the metallic contact into Dirac electrons in
graphene and vice versa. As a direct consequence of these transformations, the
ultimate performance of gated ballistic devices are much lower than expected,
in agreement with experimental results.
