IRG 3: Magnetic Heterostructures

Fundamental magnetism research continues to produce revolutionary advances in widely used technologies such as magnetic data storage while catalyzing development of completely new approaches to memory and sensing. Examples include the recent commercialization of non-volatile magnetic random access memory (MRAM) based on magnetic tunnel junctions as well as the growing family of sensors based on giant magnetoresistance. A vital requirement in all of these technologies is the integration of magnetic and non-magnetic materials into precisely engineered hetero- and nanostructures. This capability, when combined with the incorporation of new materials with precisely engineered magnetic properties, provides the freedom to create novel devices with enormous potential for new functionality. Realizing this potential, however, requires that the fundamental understanding of spin transport and dynamics, both in bulk and at interfaces, be advanced significantly. This can be achieved only through a broad, integrated effort merging precisely controlled synthesis of magnetic materials and interfaces, comprehensive atomic level structural and chemical characterization, application of powerful state-of-the-art measurement techniques, and theoretical feedback. IRG-3 brings together eight investigators with a range of expertise that is ideally suited for this approach. Our goal is to achieve a unified understanding of spin transport in magnetic heterostructures and nanostructures, focusing on three essential areas: (i) spin transport, with specific emphases on ferromagnet/semiconductor and ferromagnet/normal metal structures, (ii) spin transfer torque, focusing on switching and spin dynamics in a new class of spintronic devices, and (iii) highly-polarized materials, driven by the need to identify, synthesize, and characterize new magnetic materials with high spin polarization.