SPIN ELECTRONICS: Interplay Between Spin Transport and Magnetization Dynamics in Magnetic Nanostructures

University Of Missouri-Columbia, Columbia MO

Investigators

Abstract

This proposal was received in response to the Spin Electronics for the 21st century Initiative, Program Solicitation NSF 02-036. The proposal focuses on the interplay between current-driven magnetization dynamics and the magnetic configurational dependence of spin transport in magnetic nanostructures, i.e., to give a holistic approach to the magnetic and transport properties of magnetic nanostructures subject to a high current flow. Spin accumulation and spin current of non-collinear magnetization configuration will be obtained by solving the generalized Boltzmann equation for several magnetic nanostructures, including the multilayered pillar structure and the magnetic nanoconstriction. Magnetization dynamics in the presence of the spin accumulation and spin currents will be investigated by solving Landau-Lifshitz-Gilbert equation through micromagnetics codes. Since the spin accumulation and the magnetization dynamics are inter-dependent, the equations of motion for the non-equilibrium electron distribution and for the local magnetization must be self-consistently determined. An extensive comparison between the models developed in the program and updated (available and on-going) experimental data on spin-current induced magnetization dynamics will be given throughout this research project. The project calls for a well-balanced combination of fundamental studies and applications of the theory for spintronics devices. The outcome of the proposed research will be a general theoretical framework for understanding the magnetization dynamics of magnetic nanoconstrictions in a non-equilibrium state of conduction electrons. It is likely that the numerical modeling tools developed in this research can be widely used for experimentalists and engineers to explain, predict, and design for high-speed, high-density spintronics and other nanoscale devices. We anticipate a broad impact from this program through participation of a graduate student and a post-doc, and through partnership with industry. The research results will be integrated into an emerging course of the frontier of magnetism and magnetic materials that the PI intends to develop.