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

项目标题：可规模化生产使用受控单光子发射和吸收的新型电子设备的工程材料非技术：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。尽管科学家们多年来就已经知道，单光子或单电子工作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工作的可靠设备是极其困难的。例如，以前建造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，因为这些发射器是在随机位置形成的，不是完全相同的。受资助的研究人员将设计一种新材料来克服这一限制。首先，通过在发射器生长的表面预制图案，发射器将被迫在指定的位置生长。其次，每个地点将包含一对发射器，它们之间的相互作用可以被控制，以将发射量调整到设备运行所需的值。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、家长和教师进行持续的接触。技术：长期以来，工作在单光子、电荷和自旋的量子极限下的光电设备一直被视为量子设备技术的一个有前途的平台。这些量子技术承诺了许多进步，包括从根本上安全的信息传输模式和具有非常低检测阈值的精致传感器。理想的器件将利用晶片规模的半导体加工方法来创建发射、布线、操纵和吸收单光子的片上光子器件。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创造光学活性纳米结构的挑战的阻碍，这些结构既具有位置的空间控制，又具有对发射能量的光谱控制。该项目所采用的方法通过利用分子束外延生长方面的两个最新进展来克服这些挑战。首先，预先图案化的衬底将被用来在空间上控制光学质量不重要的“模板”量子点(QD)的成核。为了从用于光子发射和吸收的量子点获得高光学质量，将使用一系列这样的“模板”量子点将空间图案转移到与预图案化表面完全分开的生长表面。其次，光学活性结构将是沿生长轴堆叠的两个量子点的复合体，这样施加的电场就可以用来调节光学吸收和发射波长。PI先前对这些耦合的量子点对所做的工作表明，它们可以在至少比单个量子点可用的范围大一个数量级的范围内调节光发射波长。该团队将把量子点对嵌入到p-i-n二极管结构中，该结构能够对单个量子点对施加局部电场。每个QD对的单独波长可调谐性提供了与目标光子器件波长确定的光谱重叠的机制。

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.