Observation of Exciton-Phonon Sideband in Individual Metallic Single-Walled Carbon Nanotubes

TL;DR

This study provides direct evidence of excitons in individual metallic single-walled carbon nanotubes through observation of an exciton-phonon sideband, highlighting strong electron-phonon interactions in these quasi-one-dimensional systems.

Contribution

First experimental observation of an exciton-phonon sideband in a metallic SWCNT, confirming excitonic effects in metallic states.

Findings

Exciton-phonon sideband observed at 0.19 eV from the optical transition

Estimated static dielectric constant of 10 for the SWCNT

Evidence of strong electron-phonon coupling in metallic SWCNTs

Abstract

Single-walled carbon nanotubes (SWCNTs) are quasi-one-dimensional systems with poor Coulomb screening and enhanced electron-phonon interaction, and are good candidates for excitons and exciton-phonon couplings in metallic state. Here we report back scattering reflection experiments on individual metallic SWCNTs. An exciton-phonon sideband separated by 0.19 eV from the first optical transition peak is observed in a metallic SWCNT of chiral index (13,10), which provides clear evidences of excitons in metallic SWCNTs. A static dielectric constant of 10 is estimated from the reflectance spectrum.