Phonon induced Rabi frequency renormalization of optically driven single InGaAs/GaAs quantum dots

TL;DR

This paper investigates how phonons influence the Rabi frequency in optically driven InGaAs/GaAs quantum dots, revealing a phonon-induced renormalization effect analogous to the Lamb shift, across various temperatures and pulse areas.

Contribution

It demonstrates that phonon fluctuations cause Rabi frequency renormalization in quantum dots, extending understanding of exciton-phonon interactions in solid-state quantum systems.

Findings

Rabi rotation decay is nonmonotonic at high driving fields.

Rabi frequency decreases with increasing pulse area.

Rabi frequency increases with temperature.

Abstract

We study optically driven Rabi rotations of a quantum dot exciton transition between 5 and 50 K, and for pulse-areas of up to $14\pi$. In a high driving field regime, the decay of the Rabi rotations is nonmonotonic, and the period decreases with pulse-area and increases with temperature. By comparing the experiments to a weak-coupling model of the exciton-phonon interaction, we demonstrate that the observed renormalization of the Rabi frequency is induced by fluctuations in the bath of longitudinal acoustic phonons, an effect that is a phonon analogy of the Lamb-shift.