Toward Spin- and Valleytronic Devices

自旋电子学和最近的谷电子学是固态科学和工程中的新兴领域，其利用载流子的自旋/谷自由度来实现依赖于自旋/谷电流的产生、操纵和检测的新型电子器件。这种操纵预计将影响量子计算领域，因为自旋/谷是在量子计算机中记录量子比特信息的候选者。这里提出的项目的重点是研究分层半导体结构中清洁载流子系统的弹道输运。我们的目标是展示和表征一些电子设备，如自旋干涉装置，自旋过滤器，谷过滤器，其操作依赖于自旋和/或谷自由度的操纵。该项目包括一个全面的教育部分，包括研究生和本科生培训和课程编制。 外联活动包括为新泽西学校的K-12学生、公共图书馆和普林斯顿大学的教师培训项目开发演示工具包。 所提出的项目的主要目标是展示和表征一些电子设备，其操作依赖于自旋和/或谷自由度的操纵。这些包括自旋干涉装置、自旋过滤器和谷型过滤器。该器件主要基于两种不同的载流子系统：（1）GaAs量子威尔斯中的二维空穴系统，它具有强的和可调的自旋-轨道相互作用;（2）AlAs量子威尔斯中的二维电子系统，其中电子占据具有可调密度的导带谷，并且还具有大的Lande有效g因子，使得它们可以容易地被自旋极化。这些项目将涉及使用现代晶体生长和光刻技术制造各种器件，以及传输测量。这些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/或谷电子学和量子计算等新兴领域的进步至关重要。

Spintronics and, more recently, valleytronics, are emerging areas in solid state science and engineering that utilizes carriers' spin/valley degrees of freedom to realize novel electronic devices that rely on the creation, manipulation, and detection of spin/valley currents. Such manipulation is expected to impact the field of quantum computing, as spin/valley are candidates for registering the quantum bit of information in quantum computers. The focus of the projects proposed here is to study ballistic transport in clean carrier systems in layered semiconductor structures. The goal is to demonstrate and characterize a number of electronic devices such as spin-interference device, spin-filter, and valley-filter, whose operation relies on the manipulation of spin and/or valley degrees of freedom. The project incorporates a comprehensive educational component, including graduate and undergraduate students training and curriculum development. Outreach activities involve developing demonstration kits for K-12 students in New Jersey schools, for public libraries and for teachers training programs at Princeton University. The main goal of the proposed projects is to demonstrate and characterize a number of electronic devices whose operation relies on the manipulation of spin and/or valley degrees of freedom. These include a spin-interference device, a spin-filter, and a valley-filter. The devices will be based mainly 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) 2D electron system in AlAs quantum wells where the electrons occupy conduction band valleys with tunable densities, and also have a large Lande effective g-factor so that they can be easily spin-polarized. The projects will involve fabrication of various devices using modern crystal growth and lithography techniques, and transport measurements. The projects 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/or valleytronics and quantum computing.