With its direct correspondence to the electronic structure, angle-resolved photoemission spectroscopy (ARPES) is a ubiquitous tool for the study of solids. When extended to the temporal domain, time-resolved ARPES offers the potential to move beyond equilibrium properties, exploring both the unoccupied electronic structure as well as its dynamical response under ultrafast perturbation . Historically, ultrafast extreme ultraviolet sources have required compromises that make it challenging to achieve a high energy resolution, while producing sufficiently high photon energies and flux. In this talk I will discuss novel opportunities arising from the development of ultrafast laser-based sources generating ultraviolet photons in the 6-40 eV range, with 190 fs and 20 meV time and energy resolutions, respectively . On the high-temperature superconducting cuprates, we have obtained evidence for the collapse of superconductivity via ultrafast quenching of phase coherence , the emergence of the pseudogap from short-range spin-correlations in electron doped cuprates , as well as the Fermi-liquid-like suppression of quasiparticle coherence . We have also developed a novel approach for the direct determination of mode-projected electron-phonon coupling in the time-domain, and demonstrated its application to the case of graphite and its Dirac-like dispersion. Measuring the characteristic time scale for quantized energy-loss processes of photo-injected electrons at the K point allows for the direct, quantitative extraction of the electron-phonon matrix elements, for specific modes, and with unprecedented sensitivity .
 M. Zonno, F. Boschini, A. Damascelli, JESRP 251, 147091 (2021).
 A.K. Mills et al., Rev. Sci. Instrum. 90, 083001 (2019).
 F. Boschini et al., Nature Materials 17, 416 (2018).
 F. Boschini*, M. Zonno*, et al., npj Quantum Mater. 5, 6 (2020).
 M. Zonno, F. Boschini, et al., Phys. Rev. B 103, 155109 (2021).
 M.X. Na, A.K. Mills, et al., Science 366, 1231 (2019).
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