Optical vortex driven charge current loop and optomagnetism in fullerenes

Abstract

Endohedral molecular magnets, e.g. as realized in fullerenes containing $\rm DySc_{2}N$, are promising candidates for molecular electronics and quantum information processing. For their functionalization an ultrafast local magnetization control is essential. Using full ab-initio quantum chemistry calculations we predict the emergence of charge current loops in fullerenes with an associated orbital magnetic moment upon irradiation with weak light vortex pulses that transfer orbital angular momentum. The generated current is controllable by the frequency, the vortex topological charge, and the intensity of the light. Numerical and analytical results show that an ultraviolet vortex femtosecond pulse with an intensity $\sim10^{13}$ W/cm$^2$ generates non-invasively nA unidirectional surface current with an associated magnetic field of hundreds $\mu$T at the center of the fullerene.