Spin Electronics

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Abstract-0200172 Sankar Das Sarma, U of MD College Park This proposal requests funding for comprehensive theoretical and computational research on spin electronics involving active control and manipulation of spin dynamics in electronic materials. The main thrust of the proposal understands in quantitative details carrier spin transport in semiconductors (although metals and superconductors are also considered mostly in the context of semiconductor hybrid structures) from the perspective of novel multifunctional spintronic device operation. The proposed research will utilize a dual approach using microscopic atomistic frilly quantum mechanical transport calculations based on modern condensed matter physics where feasible, and macroscopic device simulation type phenomenological analyses based on the drift diffusion equations for realistic and complex device configurations. The goal of the proposed research is to develop the fundamental knowledge base for simulating semiconductor spintronic devices by providing quantitative theories for the mechanisms controlling spin injection into semiconductors, spin relaxation and coherence, spin transmission across interfaces, spin dependent scattering, spin-polarized tunneling, and spin-polarized current flow in inhomogeneous (particularly bipolar) structures. The proposed research will obtain qualitative and quantitative understanding of the relationships between specific materials systems and prototypical device structures and spin polarized transport behavior. The proposal seeks to carry out the generalization of the existing electronic transport theories including both the microscopic atomistic transport theory based on the Boltzmann equation approach, and the phenomenological device modeling theories based on the drift diffusion approach, which form the foundation of modern microelectronics device simulation studies allows arbitrary spin-polarized densities and spin-polarized currents for both electrons and holes in general bipolar systems in the presence of external an electric fields, magnetic fields and possibly external radiation fields. The proposed theory will include important microscopic processes such as surface interface roughness scattering, spin-orbit coupling, magnetic scattering from impurities, band structure effects, interface spin sensitivity, size quantization effects, and quantum interference and phase coherence effects (when the situation demands). The goal of the proposal is to develop the definitive fundamental transport theory for spin electronics. The proposed research will utilize two graduate students, who will he carrying out their PhD's in spintronics, thus developing the human resource base for the projected spin electronics technology.