OP: Spatial and spectral control of quantum dot single photon emitters for scalable photonic devices

摘要非技术：现代光子和电子设备分别通过产生和传输数千个光子或电子来运行。尽管科学家们多年前就知道，使用单光子或单电子运行的设备可以实现革命性的新功能，但要设计出在这种水平上运行的可靠设备是极其困难的。例如，先前试图构建一种包含许多独立但相同的单光子发射器的材料的努力失败了，因为发射器是在随机位置形成的，并且不相同。受资助的研究人员将设计一种克服这一限制的新材料。首先，通过对发射体生长的表面进行预图案化，迫使发射体在指定位置生长。其次，每个位置将包含一对发射器，它们的相互作用可以被控制，以将发射调整到设备操作所需的值。这项工作将包括与一所经济困难学生比例极高的小学的学生、家长和教师持续接触。技术：在单光子、电荷和自旋的量子极限下运行的光电器件一直被视为量子器件技术的一个有前途的平台。这些量子技术有望取得许多进步，包括从根本上安全的信息传输模式和具有极低检测阈值的精致传感器。理想的器件将利用晶圆级半导体加工方法来制造芯片上的光子器件，该器件可以发射、路由、操纵和吸收单个光子。这种装置的基本组成部分必须是具有量子化能态的单一光学活性纳米结构。然而，为单光子技术创建芯片可扩展平台的努力一直受到制造光活性纳米结构的挑战的阻碍，这些纳米结构既要对其位置进行空间控制，又要对其发射能量进行光谱控制。通过利用分子束外延生长的两项最新进展，本项目所采取的方法克服了这些挑战。首先，将使用预图板来空间控制光学质量不重要的“模板”量子点（QDs）的成核。为了从用于光子发射和吸收的量子点中获得高光学质量，将一系列这些“模板”量子点用于将空间图案转移到与预图案表面良好分离的生长表面。其次，光活性结构将是两个量子点沿生长轴堆叠的复合体，这样施加的电场可以用来调节光吸收和发射波长。PI先前对这些耦合量子点对的研究表明，它们可以在比单个量子点大至少一个数量级的范围内调谐光发射波长。该团队将把量子点对嵌入p-i-n二极管结构中，使电场局部应用于单个量子点对。每个量子点对的波长可调性提供了与目标光子器件波长确定的光谱重叠机制。

Project title: Engineering materials for the scalable production of new electronic devices that use controlled emission and absorption of single photons AbstractNon-Technical: Modern photonic and electronic devices operate via the generation and transmission of many thousands of photons or electrons, respectively. Although scientists have known for many years that devices that operate with single photons or single electrons could enable revolutionary new functionality, it is extremely difficult to engineer reliable devices that operate at this level. For example, previous efforts to build a material that contains many independent but identical single photon emitters have failed because the emitters are formed at random locations and are not identical. The supported researchers will engineer a new material that overcomes this limit. First, the emitters will be forced to grow at specified locations by pre-patterning the surface on which the emitters grow. Second, each site will contain a pair of emitters whose interaction can be controlled to tune the emission to the value desired for device operation. This work will include sustained engagement with the students, parents, and teachers of an elementary school with an extremely high percentage of economically-disadvantaged students.Technical: Optoelectronic devices that operate at the quantum limit of single photons, charges, and spins have long been viewed as a promising platform for quantum device technologies. These quantum technologies promise many advances, including fundamentally secure modes of information transmission and exquisite sensors with very low detection thresholds. The ideal device would leverage wafer-scale semiconductor processing methods to create on-chip photonic devices that emit, route, manipulate, and absorb single photons. The fundamental component of such a device would have to be a single optically-active nanostructure with quantized energy states. However, efforts to create chip-scalable platforms for single-photon technologies have been hampered by the challenge of creating optically-active nanostructures with both spatial control of their position and spectral control over their emission energy. The approach to be taken in this project overcomes these challenges by leveraging two recent advances in molecular beam epitaxial growth. First, pre-patterned substrates will be used to spatially control the nucleation of "template" quantum dots (QDs) whose optical quality is unimportant. A series of these "template" QDs will be used to transfer the spatial pattern to a growth surface well-separated from the pre-patterned surface in order to obtain high optical quality from the QDs that are used for photon emission and absorption. Second, the optically-active structure will be a complex of two QDs stacked along the growth axis such that applied electric fields can be used to tune the optical absorption and emission wavelengths. Prior work on these coupled QD pairs by the PI shows that they can tune optical emission wavelengths over a range at least one order of magnitude larger than that available from single QDs. The team will embed the QD pairs within a p-i-n diode structure that enables the local application of electric fields to individual QD pairs. The individual wavelength tunability of each QD pair provides the mechanism for deterministic spectral overlap with target photonic device wavelengths.