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Total Tomography of Nonplanar Heterostructures for Quantum Information Processing

用于量子信息处理的非平面异质结构的全断层扫描

基本信息

批准号：
1905768
负责人：
Lincoln Lauhon
金额：
$ 43.7万
依托单位：
Northwestern University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2022-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905768&HistoricalAwards=false
关键词：
Total Tomography Nonplanar Heterostructures Quantum

项目摘要

Nontechnical description: Semiconducting materials, particularly alloys composed of group III and group V elements, are extensively used in devices that process information electronically and convert electrical currents to light, enabling fast and efficient communication considered essential in modern society. Different III-V semiconductors can be combined in heterostructures at the nanometer scale to make devices with the potential to process information in entirely new ways by exploiting quantum mechanics. This project is using advanced deposition and characterization methods with the goal to develop fundamental understanding of how semiconducting alloys can be formed into nanoscale wires with superconducting contacts to produce new modes of information storage, computation, and communication. Furthermore, this project aims to maintain the competitiveness of the United States in new information technologies and the future workforce. Towards that end, graduate students are trained in cutting-edge three-dimensional characterization methods at Northwestern University and in national laboratories on materials systems relevant to quantum technologies.Technical description: Substrate-templated nanowire heterostructures grown in network topologies are candidates for quantum computing schemes involving Majorana quasiparticles. Band-offsets in narrow band-gap III-As/Sb semiconductors can produce the required confinement potentials for electrons, but heterostructures must be grown with the appropriate size, geometry, and precision to enable the desired coupling to metal and superconducting contacts. The goal of this project is to correlate the composition, strain, and electronic structure of III-As/Sb heterostructures in three dimensions to understand how composition and strain influence nanostructure growth and electronic properties, particularly the spatial distribution of free carriers in quasi-one-dimensional bands with strong spin-orbit coupling. Optical properties of quantized emitters in these heterostructures are also investigated. Atom probe tomography is used to measure three-dimensional nanoscale composition fields of III-As/Sb nanowire heterostructures. Based on these composition data, finite element models of relaxed physical structure are used to simulate and interpret synchrotron-based single nanowire x-ray diffraction and imaging. The combined strain and composition data, including dopant distributions measured by atom probe tomography, are used to develop models of nanostructure growth and electronic properties. Correlated single nanowire cathodoluminesence provides spatially resolved measurements of band-gap and active carrier concentrations, and correlated transmission electron microscopy measurements constrains atom probe and x-ray reconstructions of composition and strain, respectively.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术性描述：半导体材料，特别是由第III族和第V族元素组成的合金，广泛用于电子处理信息并将电流转换为光的设备中，从而实现被认为是现代社会必不可少的快速有效的通信。不同的III-V族半导体可以在纳米级的异质结构中组合，从而使器件具有通过利用量子力学以全新方式处理信息的潜力。该项目使用先进的沉积和表征方法，目标是发展对半导体合金如何形成具有超导触点的纳米级导线的基本理解，以产生新的信息存储，计算和通信模式。此外，该项目旨在保持美国在新信息技术和未来劳动力方面的竞争力。为此，研究生在西北大学和国家实验室接受尖端三维表征方法的培训，这些实验室研究与量子技术相关的材料系统。技术描述：在网络拓扑中生长的衬底模板纳米线异质结构是涉及马约拉纳准粒子的量子计算方案的候选者。窄带隙III-As/Sb半导体中的带偏可以产生电子所需的限制电势，但是异质结构必须以适当的尺寸、几何形状和精度生长，以实现与金属和超导接触的所需耦合。该项目的目标是将III-As/Sb异质结的成分，应变和电子结构在三维空间中相关联，以了解成分和应变如何影响纳米结构的生长和电子特性，特别是具有强自旋轨道耦合的准一维带中自由载流子的空间分布。量子化的发光体在这些异质结的光学性质进行了研究。利用原子探针层析成像技术对Ⅲ-As/Sb纳米线异质结构的三维纳米尺度组分场进行了测量。基于这些组成数据，松弛的物理结构的有限元模型被用来模拟和解释基于同步加速器的单纳米线X射线衍射和成像。结合应变和成分的数据，包括原子探针断层扫描测量的掺杂剂分布，用于开发纳米结构生长和电子特性的模型。相关的单纳米线阴极发光提供了带隙和活性载流子浓度的空间分辨测量，相关的透射电子显微镜测量限制了原子探针和X射线重建的组成和strain.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。