Andrea Cavalleri

Abstract:

We report possible light-induced superconductivity in the organic molecular solid K3C60, a superconductor at equilibrium below Tc=20 K. In our experiment we excited this alkali-doped fulleride with strong femtosecond pulses, tuned to be resonant with local molecular vibrational modes. By means of THz time-domain spectroscopy, we detected the pump-induced changes in the conductivity spectrum as a function of pump-probe time delay. Strikingly, at temperatures up to 100 K, we measured a light-induced response with the same optical properties of the equilibrium superconductor. An interpretation in terms of non-linear coupling between different vibrational modes may give hints to explain this emergent physics away of equilibrium.