Related Experiment Video
Updated: Sep 12, 2025

An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
Published on: October 23, 2018
Coupled Femtoexcitons, Free Carriers, and Light
D Gill1, S Shallcross1, W Chen1,2
1Max-Born-Institute for Non-linear Optics and Short Pulse Spectroscopy, Max-Born Strasse 2A, 12489 Berlin, Germany.
None:
Nonequilibrium quantum matter generated by ultrafast laser light opens new pathways in fundamental condensed matter physics, as well as offering rich control possibilities in "tailoring matter by light". Here we explore the coupling between free carriers and excitons mediated by femtosecond-scale laser pulses. Employing monolayer WSe2 and an ab initio treatment of pump-probe spectroscopy, we find that, counterintuitively, laser light resonant with the exciton can generate massive enhancement of the early-time free-carrier population. This exhibits a complex dynamical correlation to the excitons, with an oscillatory coupling between the free carrier population and exciton peak height that persists. Our results both unveil "femtoexcitons" as possessing rich femtosecond dynamics as well as, we argue, allow tailoring of early-time light-matter interaction via laser pulse design to control simultaneously excitonic and free-carrier physics at ultrafast times.
More Related Videos
08:04Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
07:39Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons
Published on: July 21, 2018
Related Concept Videos
Carrier Generation and Recombination
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
Interaction of EM Radiation with Matter: Spectroscopy
Coupled Reactions
Energy in adenosine triphosphate or ATP molecules is easily accessible to do work. ATP powers the majority of energy-requiring cellular reactions....
Photoluminescence: Applications
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
Photoreceptors and Visual Pathways