Spintronics News, Resources & Information
Spintronics is the new science of computers and memory chips that are based on electron spin rather than (or in addition to) the charge (used in electronics). Spintronics is an exciting field that holds promise to build faster and more efficient computers and other devices
Researchers from the US DoE's Argonne National Laboratory discovered that a pure-spin current can be created in materials that are insulators. Previously it was thought that such a current is possible in magnetic materials only.
The researchers generated a magnetic field on a layer of ferromagnetic YIG (yttrium iron garnet) on a substrate of paramagnetic GGG (gadolinium gallium garnet). To their surprise, the spin current was stronger in the GGG than it was in the YIG. They actually do not know how this works - and understanding it is the next step in their research.
Researchers from Switzerland's EPFL discovered that electrons can jump through spins (spin cross-over) much faster than previously thought - indeed 100,000 times faster!
Spin cross-over is used in many technologies today (such as energy conversion systems, cancer phototherapy and OLED devices). It was believed to be too slow to be used in electronics/spintronics circuits - but now that may change and open a new route to spintronics devices.
Researchers from the U.S. Naval Research Laboratory (NRL) developed a new type of room-temperature tunnel device structure in which the tunnel barrier and transport channel are both made of graphene.
In this new design, hydrogenated graphene acts as a tunnel barrier on another layer of graphene for charge and spin transport. The researchers demonstrated spin-polarized tunnel injection through the hydrogenated graphene, and lateral transport, precession and electrical detection of pure spin current in the graphene channel. The team sasy that the spin polarization values are higher than those found using more common oxide tunnel barriers, and spin transport at room temperature.
Researchers from the University of Chicago managed to line-up nuclear spins in a consistent and controllable way, on silicon-carbide, a high-performance and practical material. The technique uses light to polarize the spins - and is performed at room temperature.
Nuclear spins are normally randomly oriented, and the known methods of aligning them are complicated - and not entirely reliable. This is mostly because the spin of a nucleus is tiny - about 1,000 times smaller than the spin of an electron. The new technique is relatively simple and manages to align the spin of more than 99% spins in a Silicon Carbide nuclei.
Researchers from the University of Bath and international collaborators have developed a technology that enabled them to polarize valleys in silicon in the steady state, and demonstrated that valley polarization can make spin polarization easier. This may have useful implications towards building spintronics devices.
Researchers from Japan's Kyoto University and Osaka University have demonstrated that spin currents can travel more than half a micrometer on a thin doped-germanium sheet. Up until now this has only been demonstrated in very low temperatures (below 225 Kelvin).
Germanium has a higher electron mobility than silicon and a particular lattice symmetry that should reduce much of the electrons spin relaxation. But the material is not magnetic and so measuring spin transport is not easy because spin currents have to be created in a magnetic material and injected into germanium.
This book provides an introduction to spintronics-based ultra-low power and highly reliable computing. It discusses spintronics logic from device-level to the system-level, and includes information on magnetic memory cells, device modeling, hybrid circuit structure, design methodology, CAD tools, and technological integration methods.