Ballistic Transport in 2D Carrier Systems: Role of Spin and Valley Degrees of Freedom

自旋电子学是固体科学与工程中的一个新兴领域。其广泛的目标是利用载流子、自旋来实现依赖于自旋和自旋电流的创造、操纵和检测的新型电子设备。如果成功的话，这种自旋操纵也可能影响量子计算的更奇特的领域，因为自旋是在提议的量子计算机中记录量子比特信息的主要候选。该项目的目标是探索在调制掺杂半导体中清洁的二维载流子系统中的弹道输运。该项目包括制造和研究一些设备，这些设备的操作依赖于自旋和/或谷自由度的操纵。该器件将基于两种不同的载流子系统：(1)GaAs量子阱中的二维空穴系统具有强且可调谐的自旋轨道相互作用；(2)AlAs量子阱中的二维电子系统，其中电子占据密度可调谐的导带谷，并且具有较大的朗德有效g因子，因此电子容易自旋极化。该项目将涉及通过分子束外延的基本材料晶体生长，使用现代光刻技术制造各种设备，以及传输测量。智力优势：该项目将有助于对半导体结构中的弹道输运的基本理解。这些知识对于自旋电子学和量子计算等新兴领域的进步至关重要。它还可能导致不可预见的设备概念的发展。更广泛的影响：该项目的影响将在科学界和其他领域看到。研究结果将通过出版物和会议报告传达给专业以及一般科学和工程社区，其中该主题引起了极大的兴趣。从长远来看，这一领域的进步也将使社会受益，因为它可能导致新的电子设备和信息处理系统。该项目包含高质量和全面的教育组成部分。这将导致学生在关键的，国家的最先进的科学和技术领域的教育，包括制造，表征和高质量的层状半导体结构的物理。在这些领域训练有素的学生将是美国和世界其他地区的宝贵资源。PI还将尽一切努力吸引代表性不足群体的学生参加这个项目。PI致力于为公众提供更广泛的科学和工程教育。这个项目的一些主题和结果将被纳入他在普林斯顿大学教授的本科和研究生课程。PI还将参与与本提案主题密切相关的电力和磁力领域的各种K-12示范和教师培训计划。这些活动包括在地区学校和普林斯顿大学的培训会议、工具包开发和演示。

Spintronics is an emerging area in solid state science and engineering. Its broad goal is to utilize carriers, spin to realize novel electronic devices that rely on the creation, manipulation, and detection of spin and spin-currents. If successful, such manipulation of spins could also impact the even more exotic field of quantum computing, as spin is the leading candidate for registering the quantum bit of information in the proposed quantum computers. The goal of this project is to explore ballistic transport in clean, two-dimensional carrier systems in modulation-doped semiconductors. The project includes the fabrication and study of a number of devices whose operation relies on the manipulation of spin and/or valley degrees of freedom. The devices will be based on two different carrier systems: (1) two-dimensional hole system in GaAs quantum wells which possesses a strong and tunable spin-orbit interaction, and (2) two-dimensional electron system in AlAs quantum wells where the electrons occupy conduction band valleys with tunable densities, and have a large Lande effective g-factor so that the electrons can be easily spin-polarized. The project will involve crystal growth of the basic materials via molecular beam epitaxy, fabrication of various devices using modern lithography techniques, and transport measurements.Intellectual merit: The project will contribute to the fundamental understanding of the ballistic transport in semiconductor structures. Such knowledge is essential for advancements in the emerging fields of spintronics and quantum computing. It can also lead to the development of unforeseen device concepts. Broader impacts: The impact of the project will be seen in the scientific community and beyond. Results of the research will be communicated through publications and conference presentations to the specialized as well as general science and engineering communities, where the topic is generating substantial interest. Progress in this area will also benefit society in the long term as it may lead to novel electronic devices and information processing systems.The project incorporates a high quality and comprehensive educational component. It will result in the education of students in critical, state-of-the art areas of science and technology, including the fabrication, characterization, and physics of high quality layered semiconductor structures. Well-trained students in these fields will be invaluable resources for the US as well as for the rest of the world. The PI will also make every effort to attract to this project students from underrepresented groups.The PI is committed to a broader education of the public in science and engineering. Some of the topics and results of this project will be incorporated into undergraduate and graduate courses that he teaches at Princeton University. The PI will also participate in various K-12 demonstrations and teacher training programs in electricity and magnetism, general areas that are closely linked to the topic of this proposal. These activities include training sessions, kit development, and demonstrations at regional school, and at Princeton University.