Invited Paper GR+AS+EM+MI+MN-TuM9
Nano-plasmonic Phenomena in Graphene
Tuesday, October 29, 2013, 10:40 am, Room 104 B
Infrared nano-spectroscopy and nano-imaging experiments have uncovered rich optical effects associated with the Dirac plasmons of graphene [Nano Lett. 11, 4701 (2011)]. We were able to directly image Dirac plasmons propagating over sub-micron distances [Nature 487, 82 (2012)]. We have succeeded in altering both the amplitude and wavelength of these plasmons by gate voltage in common graphene/SiO2/Si back-gated structures. Scanning plasmon interferometry has allowed us to visualize grain boundaries in CVD graphene. These experiments revealed that grain boundaries tend to form electronic barriers that impede both electrical transport and plasmon propagation. Our results attest to the feasibility of using electronic barriers to realize tunable plasmon reflectors: a precondition for implementation of various metamaterials concepts. Finally, we have carried out pump-probe experiments probing ultra-fast dynamics of plasmons in exfoliated graphene with the nano-scale spatial resolution.