First-principles studies of relativistic spin interactions and torques

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

NONTECHNICAL SUMMARY This award supports computational and theoretical research and education aimed at better understanding the mechanisms by which relativistic magnetic effects manifest themselves in the properties of magnetic materials and nanostructures. The ability to understand these mechanisms is critical for further progress and continued innovation in information technology. The focus of this project is on the fundamental physics relevant for emerging electronic device technologies that exploit electron spin in addition to, or instead of its electric charge. Part of this research will involve investigations of the properties of specific magnetic materials that are promising for use in such devices. The project will also study the effects arising at interfaces between different materials, which enable the operation of current and future devices. Overall, it will advance the broader goal of designing materials and nanoscale devices with desired properties through computer simulations based on fundamental principles of quantum mechanics. The project will achieve broader impacts by advancing the fundamental theory of magnetism, facilitating the design of novel magnetoelectronic devices, and through the development of new computational tools, which will be made available to the broader computational materials research community. The research will involve graduate students, who will be educated in modern electronic structure, magnetism and transport theory, and will gain experience in the use and development of state-of-the-art electronic-structure and transport codes. TECHNICAL SUMMARY This award supports computational and theoretical research and education aimed at better understanding relativistic magnetic interactions in magnetic materials and nanostructures, and their effects on transport properties. This research is based on density-functional electronic structure theory, and includes the development of computational tools for the description of relativistic magnetic interactions and spin torques based on linear-response and nonequilibrium Green's function techniques. The project will focus on elucidating the mechanisms of magnetocrystalline anisotropy in metallic antiferromagnets, electronic structure of magnetic materials of current interest, such as magnetically doped topological insulators and half-metallic ferromagnets, and spin-orbit torques in non-centrosymmetric metals and ferromagnet/heavy-metal bilayers. The central feature of this research is realistic, material-specific treatment of disorder and temperature-dependent spin fluctuations. The project will achieve broader impacts by advancing the fundamental theory of magnetism, facilitating the design of novel magnetoelectronic devices, and through the development of new computational tools, which will be made available to the broader computational materials research community. The research will involve graduate students, who will be educated in modern electronic structure, magnetism and transport theory, and will gain experience in the use and development of state-of-the-art electronic-structure and transport codes.