AI 中文总结
本研究通过生长具有10至20纳米薄GaAs覆盖层的InAs/GaAs量子点，实现了比以往小5倍的发射线宽且激子寿命不受影响，证明了薄覆盖层下仍能保持高光学质量，为近场量子光子学应用开辟了道路。
AI 中文摘要
外延量子点（QDs）被广泛认为是最佳的量子光源之一，因为它们具有良好的稳定性、亮度、量子效率和相干性。为了实现这些特性，量子点通过相对较厚的覆盖层（通常超过50纳米）来保护，以避免潜在有害的表面态的影响。这阻碍了近场效应（如基于等离激元的效应）的实现，因为这些效应可以显著增强光与物质的相互作用，因为只有当发射体与金属结构非常接近（通常为几十纳米或更少）时，才能控制自发发射动力学和发射的方向性。在这项工作中，我们报告了具有10纳米、20纳米和更标准的95纳米GaAs覆盖层厚度的InAs/GaAs量子点的生长和光学表征。值得注意的是，我们观察到发射线宽比以前报道的小5倍，且激子寿命不受干扰。这些结果表明，即使发射体与表面的距离减小，外延量子点的高光学质量也能得以保持，这为利用相干且稳定的发射体探索近场光与物质相互作用开辟了道路，适用于量子技术应用。
英文摘要
Epitaxial quantum dots (QDs) are widely recognised as one of the best quantum light sources, given their good stability, brightness, quantum efficiency and coherence. To reach such properties, QDs are protected from potentially detrimental surface states by a relatively thick capping layer, typically exceeding 50nm. This prevents the implementation of near-field effects, like plasmonic-based ones, that can dramatically increase the light-matter interaction, since the control of the spontaneous emission dynamics and directionality of the emission can only occur if the emitter is in close proximity (typically tens of nanometers or less) from the metallic structures. In this work, we report the growth and optical characterisation of InAs/GaAs QDs with GaAs capping layer thickness of 10nm, 20nm, and a more standard 95nm. Remarkably, we observe emission linewidths up to 5 times smaller than previously reported, with unperturbed excitonic lifetimes. These results demonstrate that the epitaxial QD's high optical quality can be maintained even when the emitters are at reduced distances from the surface, opening the path for the exploration of near-field light-matter interactions with coherent and stable emitters, suitable for quantum technology applications.
