  The exceptional electronic properties of monoatomic thin graphene sheets
triggered numerous original transport concepts, pushing quantum physics into
the realm of device technology for electronics, optoelectronics and
thermoelectrics. At the conceptual pivot point is the particular twodimensional
massless Dirac fermion character of graphene charge carriers and its volitional
modification by intrinsic or extrinsic means. Here, interfaces between
different electronic and structural graphene modifications promise exciting
physics and functionality, in particular when fabricated with atomic precision.
In this study we show that quasiperiodic modulations of doping levels can be
imprinted down to the nanoscale in monolayer graphene sheets. Vicinal copper
surfaces allow to alternate graphene carrier densities by several 10^13
carriers per cm^2 along a specific copper high-symmetry direction. The process
is triggered by a self-assembled copper faceting process during
high-temperature graphene chemical vapor deposition, which defines interfaces
between different graphene doping levels at the atomic level.
