Advances in femto-nano-optics: ultrafast nonlinearity of metal nanoparticlesTatjana Stoll, Paolo Maioli, Aurélien Crut, Natalia Del Fatti and Fabrice ValléeEur. Phys. J. B, 87 11 (2014) 260DOI: https://doi.org/10.1140/epjb/e2014-50515-4