The on-demand preparation of higher-order Fock states is of fundamental importance in quantum information sciences. We propose and compare different protocols to generate higher-order Fock states in solid state quantum-dot--cavity systems. The protocols make use of a series of laser pulses to excite the quantum dot exciton and off-resonant pulses to control the detuning between dot and cavity. Our theoretical studies include dot and cavity loss processes as well as the pure-dephasing type coupling to longitudinal acoustic phonons in a numerically complete fashion. By going beyond the two-level approximation for quantum dots, we study the impact of a finite exchange splitting, the impact of a higher energetic exciton state, and an excitation with linearly polarized laser pulses leading to detrimental occupations of the biexciton state. We predict that under realistic conditions, a protocol which keeps the cavity at resonance with the quantum dot until the desired target state is reached is able to deliver fidelities to the Fock state ∣5⟩ well above 40%.
@article{arxiv.2006.14531,
title = {On-demand generation of higher-order Fock states in quantum-dot--cavity systems},
author = {M. Cosacchi and J. Wiercinski and T. Seidelmann and M. Cygorek and A. Vagov and D. E. Reiter and V. M. Axt},
journal= {arXiv preprint arXiv:2006.14531},
year = {2020}
}