CAREER: Spin Dependent Phenomena in Semiconductors

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

TECHNICAL SUMMARY: This CAREER award supports theoretical research, and an education, and outreach program that focuses on the study of spin-dependent phenomena in semiconductors. In the research component: 1. The PI plans to develop a theory of spin transport and accumulation in spin-orbit coupled systems where spin manipulation is possible solely by electrical means. This study, which encompasses the spin-Hall effect, will address key issues such as disorder scattering, generalized drift-diffusion equations, and interaction effects. The PI will use several approaches that combine analytical and computational techniques at different length scales. 2. The PI aims to obtain a systematic theory of the anomalous Hall effect and anomalous transport that describes on an equal footing both extrinsic and intrinsic mechanisms responsible for the effect. This study will also merge different approaches to resolve the contradictory results obtained through microscopic and phenomenological approaches. 3. The PI will work to extend the theory of magneto-transport and magneto-optics in diluted magnetic semiconductors to include nanostructures and hybrid systems and explore new phenomena such as tunneling anisotropic magneto-resistance. The educational and outreach component has four foci: (1) The PI will incorporate, further develop, and assess several Paradigms of Physics module courses in coordination with their developers at Oregon State University. The Paradigms of Physics program consists of several short module-like-courses, taught during the junior year, that focus on key paradigms that cut across several branches of physics. This allows students to better connect many interwoven ideas in different subfields. (2) The PI will involve undergraduates in the groups research projects. (3) The PI will enhance graduate education through student participation in international collaborative research, including visits to international experimental groups. (4) The PI plans to develop outreach activities to increase public awareness of spintronics and its broad impact in society, including public lectures and the development of a website describing spintronics research at TAMU at a general level. In addition a website dedicated to the specialized diluted magnetic semiconductor research community will be further developed. NON-TECHNICAL SUMMARY: This CAREER award supports fundamental theoretical research, and an education, and outreach program that focuses on the study of phenomena in semiconductors involving the spin associated with electrons. In particular the PI will focus on fundamental questions aiming to elucidate how electric fields can drive the transport of spin. The PI aims to elucidate current controversies surrounding the interpretation of experiments in which an electric field is observed to drive a spin current in a direction perpendicular to the electric field. This phenomenon offers the potential to manipulate electron spin with an electric field and opens possibilities for new electronic devices, spintronic devices, in which their operation depends not only on the electron charge, as in an electronic device, but also on its spin. The PI will also study other phenomena involving the transport of electron spin and charge in magnetic materials and in diluted magnetic semiconductors. Diluted magnetic semiconductors are semiconductors that are doped so that they contain magnetic impurities. They combine the properties of magnets and semiconductors and are promising materials for spintronic devices. The fundamental research is interesting and important in its own right, but also contributes to the intellectual foundations of the emerging field of spintronics. The educational and outreach component has four foci: (1) The PI will incorporate, further develop, and assess several Paradigms of Physics module courses in coordination with their developers at Oregon State University. The Paradigms of Physics program consists of several short module-like-courses, taught during the junior year, that focus on key paradigms that cut across several branches of physics. This allows students to better connect many interwoven ideas in different subfields. (2) The PI will involve undergraduates in the groups research projects. (3) The PI will enhance graduate education through student participation in international collaborative research, including visits to international experimental groups. (4) The PI plans to develop outreach activities to increase public awareness of spintronics and its broad impact in society, including public lectures and the development of a website describing spintronics research at TAMU at a general level. In addition a website dedicated to the specialized diluted magnetic semiconductor research community will be further developed.