Rabi oscillations of a monolayer quantum emitter driven through its excited state

TL;DR

This paper demonstrates the coherent control of Rabi oscillations in a monolayer WSe2 quantum dot, showing how optical pulses can manipulate exciton states, advancing quantum emitter technology in atomically thin semiconductors.

Contribution

It introduces a three-level exciton model for monolayer quantum dots and experimentally verifies control of exciton populations via optical pulse parameters.

Findings

Rabi oscillations observed in monolayer WSe2 quantum dots.

Exciton population controlled by pulse area and detuning.

Potential for on-demand single photon sources in 2D materials.

Abstract

The interaction of a quantum two-level system with a resonant driving field results in the emergence of Rabi oscillations, which are the hallmark of a controlled manipulation of a quantum state on the Bloch sphere. This all-optical coherent control of solid-state two-level systems is crucial for quantum applications. In this work we study Rabi oscillations emerging in a WSe2 monolayer-based quantum dot. The emitter is driven coherently using picosecond laser pulses to a higher-energy state, while photoluminescence is probed from the ground state. The theoretical treatment based on a three-level exciton model reveals the population transfer between the exciton ground and excited states coupled by Coulomb interaction. Our calculations demonstrate that the resulting exciton ground state population can be controlled by varying driving pulse area and detuning which is evidenced by the experimental data. Our results pave the way towards the coherent control of quantum emitters in atomically thin semiconductors, a crucial ingredient for monolayer-based high-performance, on-demand single photon sources.