Light dressed-excitons in an incoherent-electron sea: Evidence for Mollow-triplet and Autler-Townes doublet

TL;DR

This paper demonstrates that excitons in an incoherent electron sea can still be dressed by light, revealing phenomena like Autler-Townes doublet, Mollow triplet, and partial scattering inhibition through experimental spectroscopy in a CdTe quantum well.

Contribution

It provides experimental evidence of light dressing of excitons amid incoherent electrons, highlighting quantum coherent effects and scattering modulation in semiconductor systems.

Findings

Observation of excitonic Autler-Townes doublet

Detection of Mollow triplet with gain

Partial inhibition of electron-exciton scattering

Abstract

We demonstrate that the interaction between excitons and a sea of incoherent electrons does not preclude excitons dressing by light. We investigate the role of exciton-electron scattering in the light dressing by measuring the dynamical absorption spectrum of a modulation-doped CdTe quantum well, which shows a clear evidence for significant electron scattering of the excitonic states. We show the occurrence of dressed and correlated excitons by detecting quantum coherent interferences through excitonic Autler-Townes doublet and ac Stark splitting, which evolves to Mollow triplet with gain. We also evidence the partial inhibition of the electron-exciton scattering by exciton-light coupling.