  Here we theoretically show, by designing and manipulating spatially
inhomogeneous, non-uniform conductivity patterns across a single flake of
graphene, that this single-atom-layered material can serve as a
"one-atom-thick" platform for infrared metamaterials and transformation optical
devices. It is known that by varying the chemical potential using gate electric
and/or magnetic fields, the graphene conductivity in the THz and IR frequencies
can be changed. This versatility provides the possibility that different
"patches" on a single flake of graphene possess different conductivities,
suggesting a mechanism to construct "single-atom-thick" IR metamaterials and
transformation optical structures. Our computer simulation results pave the way
for envisioning numerous IR photonic functions and metamaterial concepts-all on
a "one-atom-thick" platform-of such we list a few here: edge waveguides, bent
ribbon-like paths guiding light, photonic splitters and combiners,
"one-atom-thick" IR scattering elements as building blocks for "flatland"
metamaterials, thin strips as flatland superlenses, and "one-atom-thick"
subwavelength IR lenses as tools for Fourier and transformation optics.
