Emergence of Floquet Behavior for Lattice Fermions Driven by Light Pulses

TL;DR

This paper investigates how noninteracting lattice fermions driven by light pulses approach Floquet behavior, identifying the minimal pulse durations required for the system to exhibit Floquet-like properties.

Contribution

It provides a quantitative analysis of the pulse lengths needed for noninteracting fermions to display Floquet characteristics, bridging the gap between theoretical models and experimental conditions.

Findings

Floquet behavior emerges after finite pulse durations

Minimal pulse length depends on system parameters

Approach to Floquet limit is characterized in the infinite-dimensional limit

Abstract

As many-body Floquet theory becomes more popular, it is important to find ways to connect theory with experiment. Theoretical calculations can have a periodic driving field that is always on, but experiment cannot. Hence, we need to know how long a driving field is needed before the system starts to look like the periodically driven Floquet system. We answer this question here for noninteracting band electrons in the infinite-dimensional limit by studying the properties of the system under pulsed driving fields and illustrating how they approach the Floquet limit. Our focus is on determining the minimal pulse lengths needed to recover the qualitative and semiquantitative Floquet theory results.