Temporal response of nonequilibrium correlated electrons

TL;DR

This paper investigates the time-dependent current response of the spinless Falicov-Kimball model near the Mott-Hubbard transition under strong electric fields, revealing correlation-induced oscillation modulation and shifts in response onset.

Contribution

It introduces an exact nonequilibrium impurity solution to study electron dynamics in time-dependent fields, highlighting correlation effects on current oscillations and response timing.

Findings

Current exhibits Bloch oscillations with amplitude modulation.

Correlation effects reduce current magnitude and delay response onset.

Behavior observed on both sides of the metal-insulator transition.

Abstract

In this work we examine the time-resolved, instantaneous current response for the spinless Falicov-Kimball model at half-filling, on both sides of the Mott-Hubbard metal-insulator transition, driven by a strong electric field pump pulse. The results are obtained using an exact, nonequilibrium, many-body impurity solution specifically designed to treat the out-of-equilibrium evolution of electrons in time-dependent fields. We provide a brief introduction to the method and its computational details. We find that the current develops Bloch oscillations, similar to the case of DC driving fields, with an additional amplitude modulation, characterized by beats and induced by correlation effects. Correlations primarily manifest themselves through an overall reduction in magnitude and shift in the onset time of the current response with increasing interaction strength.