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Researchers developed a method to fabricate ultrathin InGaAs quantum dots embedded axially within GaAs-based nanowires by introducing small amounts of antimony (Sb) during growth. The Sb incorporation suppresses rotational twin defects and controls facet evolution, enabling the formation of abrupt, few-nanometer-thick quantum emitters at the nanowire tip. Optical characterization of individual nanowires confirmed spatially localized single-photon emission with short lifetimes around 0.51 ns and antibunching values of g(2)(0) below 0.4, validating quantum dot behavior.
Why it matters
This approach advances the monolithic integration of single-photon sources on silicon substrates, a foundational step for building scalable quantum photonic circuits and quantum communication networks. Improved defect control in nanowire growth could reduce fabrication variability and bring practical quantum devices closer to realization.
arXiv:2605.13992v1 Announce Type: new
Abstract: GaAs-based nanowires hosting active quantum heterostructures provide a promising route toward monolithic integration of single-photon sources on silicon, a key requirement for scalable quantum photonics. However, ultrathin axial quantum-emitter formation is often hindered by facet-dependent growth dynamics and rotational twins, which induce lateral overgrowth and compromise interface abruptness. Here, we develop InGaAs-based quantum emitters by tailoring facet evolution via dilute Sb incorporation, which efficiently suppresses twins and promotes confined axial insertion at the growth-front facet. This approach significantly enhances the probability of obtaining abrupt, few-nanometer-thin quantum dots at the nanowire tip. Single-nanowire optical spectroscopy reveals intense, spatially localized emission from the active region with lifetimes as short as (0.51 $pm$ 0.02) ns, and second-order photon-correlation measurements consistently exhibit pronounced antibunching with $g^{(2)}(0)<0.4$, confirming single-photon emission. These results establish a strong correlation between twin density and axial heterostructure formation, identifying defect control as a key factor in realizing monolithically integrated nanowire single-photon sources.