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

Advancing quantum information and communication technology (qICT) requires smaller and faster components with actively controllable functionalities. This work presents a novel 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 C60 molecules with resonant ultrashort light pulses, we can significantly modify the interaction at the cobalt/C60 interface, leading to a striking 60% transient shift in the frequency of the dipolar ferromagnetic resonance mode of the Cobalt. 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 paradigm for ultrafast optical control of magnetism at the nanoscale.