Spintronics–Counting on the Right Spin
Computers and electronics are the foundations of modern information processing, ranging from the mobile telephone to credit card invoicing. Bits and bytes run back and forth as electron charges between transistors, memory devices and hard drives. The electron's second important property–its spin, on which the magnetic properties of matter are based–has barely been exploited.
In the medium term, computer components produced by spintronics could consume less energy and process more quickly than today's components. And in contrast to today's chips, the information stored in these components is also retained when the computers are turned off, eliminating the time-consuming "booting" process.
Jülich researchers are developing materials and processes that communicate between electrical and magnetic properties at the level of quantum mechanics. They use supercomputers and mathematical models to explore the atomic interactions in crystals. High-resolution light and electron microscopy, as well as neutron and synchrotron experiments, provide insights into matter. In state-of-the-art ultrahigh vacuum chambers, the scientists stack various elements atomic layer by atomic layer to construct a sample with unique magnetic properties, such as spin valves that filter out electrodes with suitable spin from a current of electrodes. Or switches between magnetic states, that respond to the tiniest electric voltages or currents.
Spintronics is no longer a far-off dream of the future, however. Today, the read heads of hard drives use spin-based effects to find gigabytes of data on a surface the size of a thumbnail. The foundations for this and for spintronics were laid at Forschungszentrum Jülich. The Jülich researcher Peter Grünberg discovered the "GMR effect" used in today's hard drives over 20 years ago. For his discovery, he was awarded the Nobel Prize in Physics in 2007.