CAREER: Spin-Polarized Transport and Spintronic Devices

智力MeritThe本研究的目的是制定一个理论框架的自旋极化运输铁磁异质结，并通过开发建模工具，提出和严格评估新的自旋电子器件。使用不同的磁化方向，存储在磁性区域中的信息即使在不提供任何外部电源的情况下也可以被保存，从而为低功耗和非易失性应用开辟了可能性。然而，现有的商业自旋电子器件，基于磁阻效应，利用只有一小部分潜在的自旋为基础的应用。在稀磁半导体和半导体/金属铁磁体结中，铁磁性可以通过光学和电学来调节，从而使新型自旋晶体管和多功能器件能够无缝集成存储器和逻辑。该方法是开发一个多尺度模型，结合漂移扩散方程，广义Landauer-Buttiker形式主义，和第一性原理密度泛函理论，自洽地处理很大程度上不同的载流子密度，强烈偏离当地的电荷中性，自旋极化运输，和不均匀的铁磁性。更广泛的影响拟议的研究将与开发物理课程和广泛的学生培训紧密结合，通过路易斯·斯托克斯少数民族参与联盟为本科生积极招募代表性不足的少数民族。PI将开发一门多学科课程自旋电子学基础，涵盖固态物理，工程，材料科学和纳米技术等方面。为了传播这项研究的结果，并提供更多的曝光和培训的学生在自旋电子学和相关学科，PI将共同组织一个国际研讨会上的纳米结构的运输与橡树岭国家实验室和田纳西大学的合作。

Intellectual MeritThe objective of this research is to formulate a theoretical framework for spin-polarized transport in ferromagnetic heterojunctions and, by developing modeling tools, to propose and critically assess novel spintronic devices. Information stored in magnetic regions, using different orientations of the magnetization, can be preserved even without supplying any external power, opening possibilities for low-power and non-volatile applications. However, the existing commercial spintronic devices, based on the magnetoresistive effects, utilize only a small fraction of potential spin-based applications. In dilute magnetic semiconductors and in nonmagnetic semiconductor/metallic ferromagnet junctions ferromagnetism can be optically and electrically tuned thus enabling novel classes of spin transistors and multifunctional devices for seamless integration of memory and logic. The approach is to develop a multiscale modeling which combines drift-diffusion equations, generalized Landauer-Buttiker formalism, and first-principles density functional theory, to self-consistently treat largely varying carrier densities, strong deviations from the local charge neutrality, spin-polarized transport, and inhomogeneous ferromagnetism. Broader ImpactThe proposed research will be closely integrated with developing physics curricula and an extensive student training with active recruitment of underrepresented minorities through the Louis Stokes Alliance for Minority Participation for undergraduate students. The PI will develop a multidisciplinary course Fundamentals of Spintronics which will span aspects of solid-state physics, engineering, materials science, and nanotechnology. To disseminate the results of this research and provide additional exposure and training of students in spintronics and related disciplines, the PI will co-organize an international workshop on transport in nanostructures in collaborations with the Oak Ridge National Laboratory and the University of Tennessee.