Mansart, BarbaraLorenzana, JoseMann, AndreasOdeh, AhmadScarongella, MariateresaChergui, MajedCarbone, Fabrizio2013-10-012013-10-012013-10-01201310.1073/pnas.1218742110https://infoscience.epfl.ch/handle/20.500.14299/95147WOS:000317521600036Dynamical information on spin degrees of freedom of proteins or solids can be obtained by NMR and electron spin resonance. A technique with similar versatility for charge degrees of freedom and their ultrafast correlations could move the understanding of systems like unconventional superconductors forward. By perturbing the superconducting state in a high-T-c cuprate, using a femtosecond laser pulse, we generate coherent oscillations of the Cooper pair condensate that can be described by an NMR/electron spin resonance formalism. The oscillations are detected by transient broad-band reflectivity and are found to resonate at the typical scale of Mott physics (2.6 eV), suggesting the existence of a nonretarded contribution to the pairing interaction, as in unconventional (non-Migdal-Eliashberg) theories.text::journal::journal article::research article