Plasmon Generation by Excitons in Carbon Nanotubes


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Optically excited excitons are theoretically demonstrated to generate and amplify plasmons in individual semiconducting carbon nanotubes. Plasmons are coherent charge density waves due to the periodic opposite-phase displacements of the electron shells with respect to the ion cores. Charge density waves produce oscillating electric fields concentrated locally throughout the nanotube surface. These strong local coherent fields can be used in a variety of new tunable optoelectronic applications of carbon nanotubes, such as near-field optical probing and sensing, optical switching, enhanced electromagnetic absorption, and materials nanoscale modification. The entire process is the result of the efficient energy conversion, whereby the external electromagnetic radiation absorbed to excite excitons transfers into the energy of high-intensity coherent charge density waves, the plasmons. The process can be controlled by means of an electrostatic field applied perpendicular to the nanotube axis. [To appear in Physical Review B]

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Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2012: Advanced Materials, CNTs, Particles, Films and Composites (Volume 1)
Published: June 18, 2012
Pages: 334 - 337
Industry sector: Advanced Materials & Manufacturing
Topic: Carbon Nano Structures & Devices
ISBN: 978-1-4665-6274-5