All-Optical Ultrafast Control and Read-Out of a Single Negatively Charged Self-Assembled InAs Quantum Dot

TL;DR

This paper demonstrates ultrafast all-optical control and read-out of a single negatively charged InAs quantum dot, advancing the potential for rapid spin manipulation in quantum information applications.

Contribution

It introduces a method for ultrafast optical manipulation and measurement of a single charged quantum dot, including spin dynamics under magnetic fields.

Findings

Observation of excitation and decay of the trion state.

Demonstration of Rabi oscillations between electron and trion states.

Detection of quantum beat structures due to spin precession.

Abstract

We demonstrate the all-optical ultrafast manipulation and read-out of optical transitions in a single negatively charged self-assembled InAs quantum dot, an important step towards ultrafast control of the resident spin. Experiments performed at zero magnetic field show the excitation and decay of the trion (negatively charged exciton) as well as Rabi oscillations between the electron and trion states. Application of a DC magnetic field perpendicular to the growth axis of the dot enables observation of a complex quantum beat structure produced by independent precession of the ground state electron and the excited state heavy hole spins.