SPIN CONTROL IN ELECTRICALLY- AND OPTICALLY-GATED TOPOLOGICAL SPINTRONIC DEVICES

This proposal describes a route toward a flexible and potent materials platform that integrates diverse approaches to spintronics, including semiconductors spintronics, quantum spintronics and topological spintronics. We will explore this approach through a collaborative effort between Professor David Awschalom (University of Chicago) and Professor Nitin Samarth (Penn State University) based upon the synthesis of hybrid materials involving ferromagnetic metals, ferromagnetic semiconductors/insulators, topological insulators and single spin systems. The proposed effort focuses on a fundamental understanding of device-motivated phenomena in these materials, leveraging materials and physics discoveries made during the previous funding period. The collaborative project continues an established research record that integrates complementary state-of-the-art experimental techniques in condensed matter physics and materials physics directed towards technological goals relevant to the DOD mission. Our proposed experiments fall under the following general categories: ? Design and synthesis of new families of hybrid heterostructures that interface spintextured Dirac electrons in topological three-dimensional and two-dimensional topological insulators with metallic, semiconducting and insulating ferromagnets and with single spin environments. ? Spatio-temporal spectroscopy of patterned and opto-electronically gated topological spintronic devices. ? Opto-electronic generation & control of spin currents in topological spintronic devices. ? Coherent manipulation of localized spins (local moments, nuclear spins and defect spins) in topological spintronic devices.