Date:
A new nanowire-based quantum light source in the visible range expands the toolbox for integrated quantum photonics!
Single-photon emitters are key building blocks for emerging quantum technologies, enabling applications ranging from secure quantum communications to advanced information processing. Developing scalable and tunable quantum light sources that can be integrated into photonic devices remains one of the major challenges on the path toward practical quantum technologies.
Researchers from the NANO-SPECTROSCOPY group at Sapienza University of Rome, led by Prof. Marta De Luca, together with collaborators from the CNR - NANO Institute and Scuola Normale Superiore led by Prof. Lucia Sorba, have demonstrated high-purity single-photon emission from GaAsP quantum dots embedded in wurtzite phase GaP nanowires. The work, carried out within the activities of Spoke 4 of the NQSTI partnership, has been published in ACS Applied Materials & Interfaces and contributes to the goal of developing scalable single-photon sources for future quantum communication and information technologies.
Immagine: Top half of panel (a): Zoomed STEM image of a GaAsP (As=0.7) quantum dot embedded in a wurtzite GaP nanowire, surrounded by a thin GaP shell. Bottom half of panel (a): micro-PL spectra, at 5 K, of single GaAsP dots showing emission control via As incorporation and dot confining sizes. (b) Second order autocorrelation function of a single dot, with fit. g(2)(0) values confirm single-photon emission at 5 K and 40 K.
The nanowire platform provides greater flexibility for designing quantum light sources, combining nanoscale confinement with the possibility of engineering the emitter properties during growth. Through optimized growth conditions, the researchers achieved high-quality GaAsP quantum dots embedded in defect-free wurtzite GaP nanowires, with tunable emission across the visible spectral range. Optical measurements revealed efficient quantum light generation and highly pure single-photon emission, with stable operation up to 40 K.
These results represent the first demonstration of single-photon emission from GaAsP quantum dots embedded in wurtzite GaP nanowires. By combining controlled material growth, tunable optical properties, and the flexibility of a nanowire-based architecture, this work introduces a promising platform for next-generation quantum light sources and integrated photonic devices operating in the visible spectral range.
You can read the full article here: https://doi.org/10.1021/acsami.6c06019.