A team of physicists from the University of South Florida and the University of Kentucky have taken a big step toward the development of practical spintronics devices, a technology that could help create faster, smaller and more versatile electronic devices.
Lisenkov said an important step toward fabrication of the “holy grail” of spintronics is finding a semiconductor that has a net ‘spin’ at room temperature. The biggest challenge, however, is how to set the spin and in what material.
The USF-Kentucky team showed that a simple combination of metal atoms and a flat sheet of one atom- thick layer of pure carbon called graphene can be suitably engineered and used for this purpose.
Graphene is a relatively tangible material that can be made by peeling ordinary graphite (the same material in lead pencils) with common transparent tape. Graphene boasts properties such as a breaking strength 200 times greater than steel. It is of great interest to the semiconductor and data storage industries, electric currents that can blaze through it 100 times faster than in silicon.
Spintronic devices are hotly pursued because they promise to be smaller, more versatile, and much faster than today’s electronics and use less energy.
Using first-principles calculations, we demonstrate the existence of anisotropic ferromagnetic interactions in Co embedded graphene nanoribbons (GNRs). Spin polarization of the edge states is found to alter significantly compared to the metal-free cases. Our findings can all be well-justified as the output of the interplay between the development of an induced spin polarization in the neighborhood of the Co atoms and the maintaining of the polarization picture of the Co-free GNR. Based on our results, we propose an efficient pathway for graphene-based spintronics applications.
Spin is a quantum mechanical property with directional values “up” or “down.” This is analogous to the “on”’ or “off”’ values used with binary digital coding in modern computers. The advantage of spintronic devices is once the direction of the spin is set, no energy is required to keep it going. The spin-based data storage doesn’t disappear when the electric current stops.
Using state-of-the-art theoretical computations, the research team demonstrated that by placing cobalt atoms in graphene holes — created by removing one or two nearby carbon atoms — it is possible to set the spins in a controlled manner. That, the researchers said, is the key to practical spintronics application for graphene.