Dynamical Franz-Keldysh effect

TL;DR

This paper investigates how time-dependent electric fields influence the absorption spectra of semiconductors, revealing a significant fine structure in the dynamical Franz-Keldysh effect that can be observed experimentally.

Contribution

It introduces the concept of the dynamical Franz-Keldysh effect and predicts detailed spectral features under harmonic electric fields, expanding understanding of semiconductor responses.

Findings

Prediction of fine structure in absorption spectra

Observation of effects below and above the band-gap

Potential for experimental verification

Abstract

We introduce and analyze the properties of dynamical Franz-Keldysh effect, i.e. the change of density-of-states, or absorption spectra, of semiconductors under the influence of {\it time-dependent} electric fields. In the case of a harmonic time-dependence, we predict the occurence of significant fine structure, both below and above the zero-field band-gap, which should be experimentally observable.