Ultrafast quenching of electron-boson interaction and superconducting gap in a cuprate superconductor

Ultrafast spectroscopy makes it possible to track similarities and correlations that are not evident near equilibrium. Time- and angle-resolved photoemission measurements on cuprate high-temperature superconductor reveals that below the superconductor's critical temperature, ultrafast excitations trigger a synchronous decrease of electron self-energy and superconducting gap. In contrast, electron-boson coupling is unresponsive to ultrafast excitations above the superconductor's critical temperature and in the metallic state of a related material. These findings open a new pathway for studying transient self-energy and correlation effects in solids.