Coherent Lattice Vibrations in Carbon Nanotubes

TL;DR

This paper demonstrates the generation and detection of coherent lattice vibrations in carbon nanotubes, revealing ultrafast band gap oscillations and detailed chirality distributions through ultrashort laser pulses.

Contribution

It introduces a novel method to generate and detect coherent lattice vibrations in carbon nanotubes and maps chirality distributions with high detail.

Findings

Ultrafast band gap oscillations caused by diameter oscillations.

Detection of radial-breathing mode in single-walled carbon nanotubes.

Mapping of chirality distributions with high resolution.

Abstract

We have generated and detected the radial-breathing mode of coherent lattice vibrations in single-walled carbon nanotubes using ultrashort laser pulses. Because the band gap is a function of diameter, these diameter oscillations cause ultrafast band gap oscillations, modulating interband excitonic resonances at the phonon frequencies (3-9 THz). Excitation spectra show a large number of pronounced peaks, mapping out chirality distributions in great detail.