Quantum-dot single-photon-source performance with off-resonant pulse preparation schemes
Phys. Rev. A 113, 033709 – Published 9 March, 2026
DOI: https://doi.org/10.1103/3fd4-x4d1
Abstract
The preparation of quantum-dot qubits in the excited state is an integral part of the performance of an on-demand single-photon source (SPS). Conventional resonant excitation, an excellent approach to maximize the second-order coherence and indistinguishability of the SPS, often requires polarization filtering to remove the pump signal and isolate the qubit emission, but this results in an inherent 50% hit to the efficiency. Recent excitation schemes strategically try to exploit pulses that excite the qubit while avoiding spectral overlap to bypass this required filtering. In this work, we compare three such pumping schemes to quantify the important SPS figures of merit for off-resonant quantum-dot schemes using (1) a symmetrically detuned dichromatic pulse, (2) a notch-filtered adiabatic-rapid-passage (NARP) pulse, and (3) a swing-up of the quantum emitter population (SUPER) pulse. Due to large instantaneous pulse strengths, the dichromatic pulse suffers from phonon-induced dephasing which can lower the SPS performance by up to 50%. In contrast, the NARP and SUPER pulses are shielded from phonon coupling to differing degrees, but both maintain excellent SPS performance. The SUPER pulse can lose significant efficiency if there is variance in its constituent pulses' amplitude, pulse width, or frequency, while the NARP pulse, although potentially more difficult to realize in experiments, is robust against variance in the pulse preparation.
