Abstract
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 language | English (US) |
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Pages (from-to) | 813-819 |
Number of pages | 7 |
Journal | Nano Letters |
Volume | 12 |
Issue number | 2 |
DOIs | |
State | Published - Feb 8 2012 |
Externally published | Yes |
Keywords
- carbon nanotubes
- femtosecond dynamics
- multidimensional spectroscopy
- multiphonon assisted transition
- phonon side-band
- ultrafast
ASJC Scopus subject areas
- Bioengineering
- General Chemistry
- General Materials Science
- Condensed Matter Physics
- Mechanical Engineering