Infrared nanoscopy of dirac plasmons at the graphene-SiO₂ interface

Nano Lett. 2011 Nov 9;11(11):4701-5. doi: 10.1021/nl202362d. Epub 2011 Oct 12.


We report on infrared (IR) nanoscopy of 2D plasmon excitations of Dirac fermions in graphene. This is achieved by confining mid-IR radiation at the apex of a nanoscale tip: an approach yielding 2 orders of magnitude increase in the value of in-plane component of incident wavevector q compared to free space propagation. At these high wavevectors, the Dirac plasmon is found to dramatically enhance the near-field interaction with mid-IR surface phonons of SiO(2) substrate. Our data augmented by detailed modeling establish graphene as a new medium supporting plasmonic effects that can be controlled by gate voltage.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Computer Simulation
  • Graphite / chemistry*
  • Graphite / radiation effects*
  • Infrared Rays
  • Materials Testing
  • Models, Chemical*
  • Nanostructures / chemistry*
  • Nanostructures / radiation effects*
  • Particle Size
  • Silicon Dioxide / chemistry*
  • Silicon Dioxide / radiation effects*
  • Surface Plasmon Resonance / methods*


  • Silicon Dioxide
  • Graphite