14 DAY TRIAL // Spintronics may well be the next big step in creating a new generation of smaller, smarter and faster computers, sensors and other devices. Due to the fact that the spin of an electron is a property that makes the electron act like a tiny magnet, it can be used to encode information in electronic circuits, computers and virtually every other electronic gadget.
Practical applications such as circuits based on spintronics are promising, but for now, this promise has not been fulfilled using conventional semiconductor materials, as researchers are still trying to overcome some major problems, like the fact that single electrons can't be pinned down, and their spin-orientation is not permanent.
Now, a group of scientists at the University of California, San Diego, in the US, have come up with a theoretical model for a semiconductor-based spintronic device that performs the same logical operations as the transistors in a normal silicon chip.
Also, they proved that the spintronic logic gates in the device could be linked together to make functioning integrated circuits. The resulting spintronic silicon processors could be rewired at will, all that's needed to do that being only a change of the magnetization of the logic gates.
"This is a first proposal on how to realize a real machine out of spin-based devices," says Hanan Dery, who led the project. "We want to do this in your processor."
Their device relies on five microscopic magnetic contacts shaped like a bar, placed along a strip made of a semiconductor so the two outer pairs flank a single central one. By magnetizing the pair of bars at the end of the strip, they can control the number of electrons with spin oriented in a particular direction which can accumulate in the underlying semiconductor.
This accumulation regulates the output signal from the middle bar when scientists reverse its magnetic direction or stimulate it with an electrical signal, so this signal is in fact the result of a particular logical computation.
A single bit of information is represented by the magnetization of the two outer bars and the direction of the magnetization of the other two bars determines the logical operation that produces the signal from the central bar.
Simply put, the two end bars are the 0s and the 1s and the two inner ones check to see if they are the same or different and reflect that in the output signal.