New approaches to injection and detection of spin polarized electrons into semiconductor structures

目的：本研究项目的目标是：1)利用在InAs基材料的锌-闪锌矿结构中生长的铁磁性MnAs触点的良好结构、磁性和电学特性，在高温下获得高效的自旋注入；2)利用InAs中的Rashba效应，利用从InAs量子阱到（InGa）As探测器的共振隧穿，在偏置电场下开发可用的全半导体自旋注入器；3)通过在GaAs量子阱中嵌入超薄InAs层的Fe/GaAs自旋发光二极管（led），提高自旋注入的效率和温度稳健性。该方法是测量这些器件发出的电致发光的圆极化，从中注入的电子自旋极化，从而确定器件的效率。智力优势：在设计和发展适合每个项目的结构方面存在相当大的挑战。这些挑战包括必要结构的生长，以及了解各种生长参数如何影响结果以及如何控制它们。更广泛的影响：如果这项研究成功，它将对自旋电子学领域产生重大影响，从而可能对未来几代信息技术产生重大影响，因为它为基于砷化镓和基于砷化镓的设备提供了合适的高效注入结构。一项针对高中学生的拓展计划，目的是为他们提供波浪力学原理及其在纳米结构中的应用。

Objectives: The objectives of this research program are: 1) to obtain efficient spin injection into InAs at elevated temperatures by exploiting favorable structural, magnetic and electrical properties of ferromagnetic MnAs contacts grown in the zinc-blende structure on InAs-based materials; 2) to develop a usable all semiconductor spin injector by exploiting the Rashba effect in InAs and employing resonant tunneling from an InAs quantum well into an (InGa)As detector under a bias-created electric field; 3) to improve the efficiency and temperature robustness of spin injection from recently developed Fe/GaAs spin light emitting diodes (LEDs) which incorporate ultrathin InAs layers embedded in the GaAs Quantum wells. The approach is to measure the circular polarization of the electroluminescence emitted by these devices from which the injected electron spin polarization and therefore the device efficiency will be determined.Intellectual merit: There are considerable challenges in the design and growth of suitable structures for each of the projects to be undertaken. These challenges include the growth of the necessary structures, and understanding how the various growth parameters affect the outcome and how they can be controlled. Broader Impact : If this research is successful, it will have a significant impact on the field of spintronics, and thus possible future generations of information technology, by providing suitable efficient injection structures for both GaAs-based and InAs-based devices. An outreach program directed at high school students with the objective of providing them with exposure on the principles of wave-mechanics and its applications in nanostructures will be offered.