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arXiv · 1810.01598

A comparative study of nonequilibrium insulator-to-metal transitions in electron-phonon systems

Sharareh Sayyad·Rok Zitko·Hugo U. R. Strand·Philipp Werner·Denis Golez
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Abstract

We study equilibrium and nonequilibrium properties of electron-phonon systems described by the Hubbard-Holstein model using the 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 non-thermal metallic state with coherent quasiparticles. The same quench protocol in the one-crossing approximation results in a bad metallic state.

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Sharareh Sayyad, Rok Zitko, Hugo U. R. Strand, Philipp Werner, Denis Golez. 2018-10-03. A comparative study of nonequilibrium insulator-to-metal transitions in electron-phonon systems. https://doi.org/10.1103/physrevb.99.045118

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