Control of Giant Breathing Motion in C₆₀ with Temporally Shaped Laser Pulses

Femtosecond laser pulses tailored with closed-loop, optimal control feedback were used to excite oscillations in C₆₀ with large amplitude by coherent heating of nuclear motion. A characteristic pulse sequence results in significant enhancement of C₂ evaporation, a typical energy loss channel of vibrationally hot C₆₀. The separation between subsequent pulses in combination with complementary two-color pump-probe data and time-dependent density functional theory calculations give direct information on the multielectron excitation via the t_1g resonance followed by efficient coupling to the radial symmetric a_g(1) breathing mode.