[en] We demonstrate the ability of doubly resonant sum–frequency generation (DR-SFG) to investigate electron–phonon couplings at C60 –metal interfaces. Due to its coupling to electronic transitions, the totally symmetric Ag(2) vibration of C60 exhibits a huge enhancement of its nonlinear response for sum–frequency energies above the molecular electronic gap. We attribute this resonance to the coupling of the pentagonal pinch mode with the tiu lowest unoccupied molecular orbital (LUMO) of C60.
[Université de Liège - ULg > Département de physique > Biophotonique >]
