Two-dimensional electronic spectroscopy reveals the dynamics of phonon-mediated excitation pathways in semiconducting single-walled carbon nanotubes

Matt W. Graham, Tessa R. Calhoun, Alexander A. Green, Mark C. Hersam, Graham R. Fleming

Research output: Contribution to journalArticle

27 Scopus citations


Electronic two-dimensional Fourier transform (2D-FT) spectroscopy is applied to semiconducting single-walled carbon nanotubes and provides a spectral and time-domain map of exciton-phonon assisted excitations. Using 12 fs long pulses, we resolve side-bands above the E 22 transition that correspond with the RBM, G, G′, 2G and other multiphonon modes. The appearance of 2D-FT spectral cross-peaks explicitly resolves discrete phonon assisted population transfer that scatters excitations to the E 22 (γ-pt) state, often through a second-order exciton-phonon coupling process. All 2D-FT peaks exhibit a strong peak amplitude modulation at the G-band period (21 fs) which we show originates from an impulsive stimulated Raman process that populates a ground-state G-band vibrational coherence over a 1.3 ps phonon lifetime.

Original languageEnglish (US)
Pages (from-to)813-819
Number of pages7
JournalNano Letters
Issue number2
StatePublished - Feb 8 2012
Externally publishedYes



  • carbon nanotubes
  • femtosecond dynamics
  • multidimensional spectroscopy
  • multiphonon assisted transition
  • phonon side-band
  • ultrafast

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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