Ultrafast dynamics of the interlayer shearing mode in Au graphite nanostructures

The main objective of this research is to study the effect on gold nanostructures (~10 nm diameter size) deposited in highly ordered pyrolytic graphite (HOPG), by measuring coherent phonon spectroscopy with ultrashort (7.5 fs) laser pulses. The gold average thickness d was varied from 2 to 40 Å. We focused on the influence of gold nanoparticles in the interlayer shearing mode E
_2g
, whose energy is about 1.3 THz. We found a destructive interference of the phonon oscillations to decrease the intensity spectral peak which was critical for d=1.8 nm.