Abstract We successfully grow vertically aligned quantum ring-dot structures by Multiple Droplet Epitaxy technique. The growth is achieved by depositing GaAs quantum rings in a first droplet epitaxy process which are subsequently covered by a thin AlGaAs barrier. In a second droplet epitaxy process, Ga droplets preferentially position in the center indentation of the ring as well as attached to the edge of the ring in [ 1 1 ¯ 0 ] direction. By designing the ring geometry, full selectivity for the center position of the ring is achieved where we crystallize the droplets into quantum dots. The geometry of the ring and dot as well as barrier layer can be controlled in separate growth steps. This technique offers great potential for creating complex quantum molecules for novel quantum information technologies.

中文翻译：

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通过多液滴外延自组装垂直排列的量子环点结构

摘要 我们通过多液滴外延技术成功地生长出垂直排列的量子环点结构。生长是通过在第一次液滴外延工艺中沉积 GaAs 量子环来实现的，随后由薄的 AlGaAs 势垒覆盖。在第二个液滴外延过程中，Ga 液滴优先定位在环的中心凹痕中，并沿 [1 1 ¯ 0 ] 方向附着在环的边缘。通过设计环几何形状，实现了环中心位置的完全选择性，我们将液滴结晶成量子点。环和点以及阻挡层的几何形状可以在单独的生长步骤中控制。这项技术为为新型量子信息技术创建复杂的量子分子提供了巨大的潜力。