Observation of resonance fluorescence and the Mollow-triplet from a coherently driven site-controlled quantum dot

TL;DR

This paper demonstrates the coherent control and observation of the Mollow triplet in a site-controlled quantum dot, revealing temperature and excitation effects crucial for scalable quantum photonic devices.

Contribution

It presents the first observation of resonance fluorescence and the Mollow triplet from a lithographically positioned, site-controlled quantum dot under resonant excitation.

Findings

Observation of Mollow triplet in a site-controlled quantum dot

Linear increase of sideband widths with temperature and driving strength

Increase of Rabi splitting with temperature indicating excitonic delocalization

Abstract

Resonant excitation of solid state quantum emitters has the potential to deterministically excite a localized exciton while ensuring a maximally coherent emission. In this work, we demonstrate the coherent coupling of an exciton localized in a lithographically positioned, site-controlled semiconductor quantum dot to an external resonant laser field. For strong continuous-wave driving we observe the characteristic Mollow triplet and analyze the Rabi splitting and sideband widths as a function of driving strength and temperature. The sideband widths increase linearly with temperature and the square of the driving strength, which we explain via coupling of the exciton to longitudinal acoustic phonons. We also find an increase of the Rabi splitting with temperature, which indicates a temperature induced delocalization of the excitonic wave function resulting in an increase of the oscillator strength. Finally, we demonstrate coherent control of the exciton excited state population via pulsed resonant excitation and observe a damping of the Rabi oscillations with increasing pulse area, which is consistent with our exciton-photon coupling model. We believe that our work outlines the possibility to implement fully scalable platforms of solid state quantum emitters. The latter is one of the key prerequisites for more advanced, integrated nanophotonic quantum circuits.