Proposed robust and high-fidelity preparation of excitons and biexcitons in semiconductor quantum dots making active use of phonons

TL;DR

This paper presents a method for high-fidelity, rapid preparation of exciton and biexciton states in quantum dots by leveraging phonon interactions and tailored laser pulses, outperforming previous schemes especially under strong phonon coupling.

Contribution

It introduces robust protocols that utilize phonon-induced relaxation and adiabatic rapid passage for efficient state preparation in quantum dots, even with strong carrier-phonon interactions.

Findings

Achieves near-perfect state preparation within picoseconds.

Protocols outperform existing methods under strong phonon coupling.

Utilizes phonon relaxation to enhance robustness of quantum state control.

Abstract

It is demonstrated how the exciton and the biexciton state of a quantum dot can be prepared with high fidelity on a picosecond time-scale by driving the dot with a strong laser pulse that is tuned above the exciton resonance for exciton preparation and in resonance with the exciton transition for biexciton preparation. The proposed schemes make use of the phonon-induced relaxation towards photon dressed states in optically driven quantum dots and combine the simplicity of Rabi flopping with the robustness of adiabatic rapid passage schemes. Our protocols allow for an on-demand, fast and almost perfect state preparation even at strong carrier-phonon interaction where other schemes fail. In fact, the performance of the presented protocols is shown to be the better the stronger the carrier-phonon interaction is.