Atomistic engineering of semiconductor nanostructures for quantum information

加拿大政府的科学和技术战略将信息和通信技术以及先进制造业确定为四个优先研究领域中的两个。在这里，量子计算和量子通信被认为是关键技术之一，有可能在社会和经济福祉方面改变社会。量子计算是颠覆性的，因为它承诺了一种新的计算方式，可以有效地解决优化，编码和解码，机器学习和模拟等问题。近年来，随着IBM，Google，Microsoft，D-Wave Systems的投资，全球对该技术的兴趣呈爆炸性增长。量子通信提供了绝对安全通信的承诺，鉴于需要保护敏感数据（财务，个人）免受入侵，这是至关重要的。然而，在这两个领域，新材料和原型器件的开发经常涉及大量测试器件的制造，其成品率非常低，并且对设计细节几乎没有刻意控制，缺乏预测性理论设计工具是主要的绊脚石。* 该项目的目的是提供快速、预测性计算机辅助设计原型设备的工具，并允许优化其参数。为此，我将追求两个短期目标，并申请资助两名博士生。第一个目标将集中于开发用于限制电子或空穴的门控量子点的模拟工具，其中载流子自旋在量子计算中扮演量子比特的角色。该工具将以完全量子力学的方法解释材料的微观细节，样品的结构和外部场（电场，磁场）。该套件还将模拟相干控制，使其能够模拟量子门。在研究的基础部分，我们计划应用这个工具来研究限制空穴的点，并探索声子对载流子自旋的相干控制。在第二个目标中，我们将开发另一种完全原子化的工具来研究嵌入量子线中的量子点和量子点分子的电子特性，量子线扮演着光学腔的角色。这些系统有望成为量子通信中单光子和纠缠光子对的高效快速源，但它们的质量敏感地取决于它们的结构和几何结构的原子细节。我们的目标将是展示一个非经典光发射器的时间依赖性模拟，并指导这样一个设备的实验实现。该项目的影响在于实现量子器件的计算机辅助设计和优化，简化和指导实验工作。由于这些成果的重要性，我们期待着高水平的出版物和会议报告，以及与世界各地的实验小组的合作。

The Government of Canada's Science and Technology Strategy identifies Information and Communications Technology and Advanced Manufacturing as two of the four research priority areas. Here, quantum computing and quantum communication are considered among key technologies which have a potential to transform societies in terms of their social and economic well-being. Quantum computing is disruptive, as it promises a new way of computing, enabling efficient solutions of problems such as optimization, coding and decoding, machine learning and simulation. The recent years witnessed an explosive increase of worldwide interest in this technology, with investments by IBM, Google, Microsoft, D-Wave Systems. Quantum communication offers the promise of absolutely secure communication, which is of vital interest in light of the need to protect sensitive data (financial, personal) from intrusion. However, in both areas, the development of new materials and prototype devices frequently involves fabrication of a large number of test devices with very low yield and little deliberate control over design details, with the lack of predictive theoretical design tools being a major stumbling block. ***The aim of this project is to provide tools for fast, predictive computer-aided design of prototype devices and to allow the optimization of their parameters. To this end, I will pursue two short-term objectives, and I request funding for two PhD students. The first objective will focus on the development of a simulation tool for gated quantum dots confining electrons or holes, in which the carrier spin plays the role of the quantum bit for quantum computing. This tool will account for microscopic details of the material, the structure of the sample, and the external fields (electric, magnetic) in a fully quantum-mechanical approach. The suite will also model the coherent control, enabling it to simulate quantum gates. In the fundamental part of the study, we plan to apply this tool to study dots confining holes and explore the coherent control of the carrier spin by phonons.***In the second objective, we will develop another, fully atomistic tool to study the electronic properties of quantum dots and dot molecules embedded in quantum wires playing the role of an optical cavity. These systems hold promise as efficient and fast sources of single photons and entangled photon pairs for quantum communication, but their quality sensitively depends on atomistic details of their structure and geometry. The goal will be to demonstrate a time-dependent simulation of an emitter of non-classical light and to guide the experimental realization of such a device. The impact of this project consists in enabling computer-aided design and optimization of quantum devices, simplifying and guiding the experimental work. Due to the importance of these outcomes, we expect high-level publications and conference presentations as well as collaborations with experimental groups worldwide.**