Sayyad, Sharareh Žitko, Rok Strand, Hugo U. R. Werner, Philipp Golež, Denis 2019-01-09 We study equilibrium and nonequilibrium properties of electron-phonon systems described by the Hubbard-Holstein model using dynamical mean-field theory. In equilibrium, we benchmark the results for impurity solvers based on the one-crossing approximation and slave-rotor approximation against non-perturbative numerical renormalization group reference data. We also examine how well the low-energy properties of the electron-boson coupled systems can be reproduced by an effective static electron-electron interaction. The one-crossing and slave-rotor approximations are then used to simulate insulator-to-metal transitions induced by a sudden switch-on of the electron-phonon interaction. The slave-rotor results suggest the existence of a critical electron-phonon coupling above which the system is transiently trapped in a nonthermal metallic state with coherent quasiparticles. The same quench protocol in the one-crossing approximation results in a bad metallic state. application/pdf https://folia.unifr.ch/global/documents/307708 https://folia.unifr.ch/documents/307708/files/wer_csn.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.99.045118 info:eu-repo/semantics/openAccess License undefined Physical Review B. - 2019, vol. 99, no. 4, p. 045118 info:eu-repo/classification/udc/53 Comparative study of nonequilibrium insulator-to-metal transitions in electron-phonon systems http://purl.org/coar/resource_type/c_6501