Ultrafast Depopulation of a Quantum Dot by LA-phonon-assisted Stimulated Emission

TL;DR

This paper demonstrates ultrafast depopulation of a quantum dot via LA-phonon-assisted stimulated emission, achieving 20 ps switching with broad tunability, supported by experimental and theoretical analysis.

Contribution

It introduces a method for ultrafast quantum dot depopulation using phonon-assisted stimulated emission, with detailed experimental and theoretical validation.

Findings

Depopulation achieved within 20 ps pulse duration.

Broad tuning range of a few meV.

Experimental results match path-integral calculations.

Abstract

We demonstrate ultrafast incoherent depopulation of a quantum dot from above to below the transparency point using LA-phonon-assisted emission stimulated by a redshifted laser pulse. The QD is turned from a weakly vibronic system into a strongly vibronic one by laser driving which enables the phonon-assisted relaxation between the excitonic components of two dressed states. The depopulation is achieved within a laser pulse-width-limited time of 20 ps and exhibits a broad tuning range of a few meV. Our experimental results are well reproduced by path-integral calculations.