Photoinduced insulator-metal transition in correlated electrons -- a Floquet analysis with the dynamical mean-field theory

TL;DR

This paper introduces a novel theoretical approach combining Floquet analysis with dynamical mean-field theory to study photoinduced insulator-metal transitions in correlated electron systems, capturing nonequilibrium steady states beyond linear response.

Contribution

The authors develop a new method integrating Floquet-matrix techniques with DMFT to analyze nonequilibrium states in strongly correlated electrons under AC fields.

Findings

Intense AC fields can induce a transition from insulator to metal in the model.

The method accurately captures spectral and transport properties in nonequilibrium.

Photoinduced metallic states emerge nonlinearly from Mott-like insulators.

Abstract

In order to investigate photoinduced insulator-metal transitions observed in correlated electron systems, we propose a new theoretical method, where we combine a Floquet-matrix method for AC-driven systems with the dynamical mean-field theory. The method can treat nonequilibrium steady states exactly beyond the linear-response regime. We have applied the method to the Falicov-Kimball model coupled to AC electric fields, and numerically obtained the spectral function, the nonequilibrium distribution function and the current-voltage characteristic. The results show that intense AC fields indeed drive Mott-like insulating states into photoinduced metallic states in a nonlinear way.