Keyword Suggestions

II5.02 - Phonon Polariton Coupling of Monolayer Boron Nitride and Graphene 
April 23, 2014   9:00am - 9:15am

The 2D nature of graphene, along with its novel electronic structure, makes it an intriguing platform to study propagating surface plasmons. Behaving as an extraordinarily thin waveguide, graphene has been recently shown to support electronically tunable ,Mid-IR plasmons with optical mode volumes that are 107 times smaller than freespace, and plasmon wavelengths more than 100 times shorter. In addition to these unique effects, the extreme thinness of a monolayer graphene sheet make the plasmonic properties strongly dependent on the dielectric properties of the surrounding media. In this talk we show that the large optical confinement properties of monolayer graphene allow for the plasmonic dispersion relations to be strongly altered by the nearby optically active excitations, such as phonons or excitons. We will demonstrate, experimentally, that the phonons of just a single, underlying boron nitride (BN) sheet can be used to create new surface phonon plasmon polariton modes (SPPPs) in graphene. By studying the wavelength and doping dependence of these modes, we map out their dispersion relation and observe anti-crossing behavior between the graphene plasmon and this new SPPP mode. We further show that the high quality factor of the BN optical phonon at 170meV leads to epsilon near zero (ENZ) behavior in the SPPP mode as the wavelength varies from 160 to 600nm. These experimental observations are compared to a theoretical model that has been developed to explain optically active graphene devices, and we find good agreement.

Average Rating: (No Ratings)
  Was great, surpassed expectations, and I would recommend this
  Was good, met expectations, and I would recommend this
  Was okay, met most expectations
  Was okay but did not meet expectations
  Was bad and I would not recommend this

Keynote Address
Panel Discussion - Different Approaches to Commercializing Materials Research
Business Challenges to Starting a Materials-Based Company
Fred Kavli Distinguished Lectureship in Nanoscience
Application of In-situ X-ray Absorption, Emission and Powder Diffraction Studies in Nanomaterials Research - From the Design of an In-situ Experiment to Data Analysis