Light-driven modulation of proximity-enhanced functionalities in hybrid nano-scale systems.

Advancing quantum information and communication technology requires smaller and faster components with actively controllable functionalities. This work presents an all-optical strategy for dynamically modulating magnetic properties via proximity effects controlled by light. We demonstrate this concept using hybrid nanoscale systems composed of C₆₀ molecules proximitized to a cobalt metallic ferromagnetic surface, where proximity interactions are particularly strong. Our findings show that by inducing excitons in the C molecules with resonant ultrashort light pulses, we can significantly modify the interaction at the Cobalt/C interface, leading to a remarkable 60% transient shift in the frequency of the Co dipolar ferromagnetic resonance mode. This effect, detected via a specifically designed time-resolved Magneto-Optical Kerr Effect (tr-MOKE) experiment, persists on a timescale of hundreds of picoseconds. Since this frequency shift directly correlates with a transient change in the anisotropy field-an essential parameter for technological applications-our findings establish a new material platform for ultrafast optical control of magnetism at the nanoscale.