An Atomic Force Microscopy study of buried InAs/GaAs quantum-dot single-photon sources

传统光源在宽角度范围内发射大量光子，并且主要用于照明或成像目的。技术进步使得设备组件的尺寸可以减小到纳米级，有趣的量子力学效应也开始发挥作用。我们现在能够在原子水平上操纵物质，并按需产生单光子，这是光的最小组成部分。在最小的水平上控制光发射的能力，单光子，在技术上是具有挑战性的，但非常有趣。通信的下一次革命预计将通过实现量子设备来实现，其中光-物质相互作用被设计为使得信息可以存储在光子网络内的光学腔之间循环的单光子中。鉴于其可扩展性和片上集成的可能性，固态单光子源有望成为这些新型量子架构的构建模块。如果我们能够在单光子水平上存储信息，我们就可以以光速传输信息，并保证安全通信：不受欢迎的观察者的任何测量都会留下接收者可见的痕迹，从而揭示信息的窃取。然而，一些挑战仍然限制了量子信息技术在日常生活中的应用：所发射的光子仅在非常短的时间尺度上保持它们的特性，通常需要由外部激光器激发的低温冷却的发射器，在这个项目中，我们将研究纳米粒子的存在是如何影响信息的存储和共享的。埋在半导体板内的氧化皮发射体影响表面形态，以及这反过来如何影响所发射的单光子的性质。这项工作的成果将代表着在理解量子光源的发射特性方面向前迈出了一步，从而提高了单光子发射的质量和可靠性，这对量子计算和密码学等信息技术应用至关重要。

Conventional light sources emit a large number of photons in a wide angular range and are mainly used for illumination or imaging purposes. Technological advances have allowed the dimensions of the components of devices to be reduced to the nanometre scale, and intriguing quantum mechanical effects have come into play. We are now able to manipulate matter at the atomic level and generate single photons, the smallest constituents of light, on-demand. The ability to control light emission at its smallest level, the single photon, is technologically challenging but tremendously interesting. The next revolution in communication is expected to take place by implementing quantum devices where light-matter interaction is engineered such that information can be stored in single photons that circulate between optical cavities within a photonic network. Given their scalability and the possibility of on-chip integration, solid-state single-photon sources are expected to be the building blocks of these novel quantum architectures. If we can store information on a single photon level, we can transfer it at the speed of light with a guaranteed secure communication: any measurement by an unwanted observer will leave a trace that will be visible to the receiver, thus unveiling the steal of information. However, several challenges are still limiting the implementation of quantum information technology in everyday life: the emitted photons only preserve their properties over a very short time-scale, often requiring cryogenic-cooled emitters excited by external lasers, and networks where information can be efficiently stored and shared are still lacking.In this project we will investigate how the presence of nanometre-scale emitters buried within a semiconductor slab affects the surface morphology and how this, in return, impacts the properties of the single photons emitted. The outcome of this work will represent a step forward in the understanding of the emission properties of quantum light sources, allowing to improve the quality and reliability of single-photon emission, essential for information technology applications, like quantum computing and cryptography.