LETTER pubs.acs.org/NanoLett Graphene Plasmonics: A Platform for Strong LightMatter Interactions

bS Supporting Information Surfaces plasmons (SPs), the electromagnetic waves coupledto charge excitations at the surface of a metal, are the pillar stones of applications as varied as ultrasensitive optical biosensing,13 photonic metamaterials,4 light harvesting,5,6 op-tical nanoantennas,7 and quantum information processing.811 However, even noble metals, which are widely regarded as the best available plasmonic materials,12 are hardly tunable and exhibit large Ohmic losses that limit their applicability to optical processing devices. In this context, doped graphene emerges as an alternative, unique two-dimensional plasmonic material that displays a wide range of extraordinary properties.13 This atomically thick sheet of carbon is generating tremendous interest due to its superior electronic and mechanical properties,1420 which originate in part from its charge carriers of zero effective mass (the so-calle