Pustogow, AndrejSaito, YoheiLöhle, AnjaSanz Alonso, MiriamKawamoto, AtsushiDobrosavljević, VladimirDressel, MartinFratini, Simone2023-05-242023-05-2420212041-17231846837081http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-130804http://elib.uni-stuttgart.de/handle/11682/13080http://dx.doi.org/10.18419/opus-13061Landau suggested that the low-temperature properties of metals can be understood in terms of long-lived quasiparticles with all complex interactions included in Fermi-liquid parameters, such as the effective mass m⋆. Despite its wide applicability, electronic transport in bad or strange metals and unconventional superconductors is controversially discussed towards a possible collapse of the quasiparticle concept. Here we explore the electrodynamic response of correlated metals at half filling for varying correlation strength upon approaching a Mott insulator. We reveal persistent Fermi-liquid behavior with pronounced quadratic dependences of the optical scattering rate on temperature and frequency, along with a puzzling elastic contribution to relaxation. The strong increase of the resistivity beyond the Ioffe-Regel-Mott limit is accompanied by a ‘displaced Drude peak’ in the optical conductivity. Our results, supported by a theoretical model for the optical response, demonstrate the emergence of a bad metal from resilient quasiparticles that are subject to dynamical localization and dissolve near the Mott transition.eninfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/4.0/530article2023-03-28