Surface acoustic wave mediated carrier injection into individual quantum post nano emitters

TL;DR

This paper demonstrates a highly efficient method for injecting carriers into individual quantum posts using surface acoustic waves, enabling stable and directional emission compared to direct optical pumping.

Contribution

It introduces a novel acousto-electric technique for remote carrier injection into quantum emitters, improving stability and efficiency over traditional optical methods.

Findings

Efficient carrier injection over macroscopic distances.

Enhanced stability at high acoustic powers.

Directional emission controlled by SAW propagation.

Abstract

Acousto-electric charge conveyance induced by a surface acoustic wave is employed to dissociate photogenerated excitons. Over macroscopic distances, both electrons and holes are injected \emph{sequentially} into a remotely positioned, isolated and high-quality quantum emitter, a self-assembled quantum post. This process is found to be highly efficient and to exhibit improved stability at high acoustic powers when compared to direct optical pumping at the position of the quantum post. These characteristics are attributed to the wide matrix quantum well in which charge conveyance occurs and to the larger number of carriers available for injection in the remote configuration, respectively. The emission of such pumped quantum posts is dominated by recombination of neutral excitons and fully directional when the propagation direction of the SAW and the position of the quantum post are reversed.