Final-state read-out of exciton qubits by observing resonantly excited photoluminescence in quantum dots

TL;DR

This paper introduces a novel method for detecting excitonic qubits in quantum dots by observing resonantly excited photoluminescence, enabling high temporal resolution and suppression of background noise.

Contribution

The study demonstrates a new optical detection technique for exciton qubits using resonant excitation and emission observation with picosecond resolution.

Findings

Observation of Rabi oscillations in exciton emissions

Effective suppression of elastic scattering in the setup

Temporal resolution of emission dynamics at picosecond scale

Abstract

We report on a new approach to detect excitonic qubits in semiconductor quantum dots by observing spontaneous emissions from the relevant qubit level. The ground state of excitons is resonantly excited by picosecond optical pulses. Emissions from the same state are temporally resolved with picosecond time resolution. To capture weak emissions, we greatly suppress the elastic scattering of excitation beams, by applying obliquely incident geometry to the micro photoluminescence set-up. Rabi oscillations of the ground-state excitons appear to be involved in the dependence of emission intensity on excitation amplitude.