Spintronics breakthrough could lead to single chip for processing and memory
Using flexible organic semiconductors, researchers at Queen Mary, University of London and the University of Fribourg have made a discovery that could lead to the simultaneous storing and processing of data on the same computer chip, bringing a dramatic improvement in power efficiency and reduced weight of electronic devices.
Spintronics – a technology that exploits the magnetic properties of electrons to store and manipulate information in digital form – has experienced a very rapid surge over the last few years, and is now the preferred technology for manufacturing fast solid state drives (SSDs).
In SSDs, so-called "spin valves" harness the magnetic properties of electrons to detect data that is stored in magnetic bits; by contrast, data processing relies on streams of electrons flowing around circuits within a microchip.
The Queen Mary/Fribourg team showed that lithium fluoride (LiF), a material with an intrinsic electric field, can modify the spin of electrons transported through the spin valves. This proves that electric fields can manipulate a magnetically polarized current and could lead to computer chips that not only store data, but are capable of manipulating it as well.
The researchers shot muons – unstable subatomic particles – into layers of lithium fluoride and observed their behavior as they decayed, which offered information about the magnetic processes inside the material. Low-energy muons are unique in that they can be placed into a specific layer, making it possible to study the behavior of single layers independently.
"This is especially exciting, as this discovery has been made with flexible organic semiconductors, which are set to be the new generation of displays for mobile devices, TVs and computer monitors, and could offer a step-change in power efficiency and reduced weight of these devices," said Dr. Alan Drew, who led the research efforts. While devices that combine electron charge and spin are conceptually straightforward, this is the first time researchers have shown it is possible to proactively control the spin of electrons with electric fields.
The experiments were performed at the Paul Scherrer Institute, currently the only institution in the world in possession of the necessary equipment. A paper detailing the team's research has been published in this week's edition of the scientific journal Nature Materials.