As our current computing architecture is not getting much faster and using a lot of power, combined with the exploding demands to store information, researchers are interested in new strategies to store more information in an energy efficient way. One potential pathway is to store information at the ultimate scaling limit: a single atom. “Computers have reached fundamental limitations as to how much better they can get, creating a huge demand in materials research for alternatives. Modern computers use a lot of electricity, currently demanding more than 5 percent of the world’s electricity. Fundamental science says we can gain a lot more in energy efficiency. We are focusing on a very basic component of modern computers: a bit of memory. We use atoms because they are the smallest unit of matter and also enable us to further understand the fundamental science behind their behavior. Our current question: how can we store information within a single atom and how stable can we make that piece of information?”, first author Brian Kiraly explains.
Atoms need to stop flipping to store information
When you get down to the single atom level, atoms which are magnetic, no longer remain stable. “What defines a permanent magnet is that it has a north and a south pole, which remains in the same orientation,” professor of Scanning Probe Microscopy Alexander Khajetoorians explains, “But when you get down to a single atom, the north and south pole of the atom start to flip and do not know what direction they should point, as they become extremely sensitive to their surroundings. If you want a magnetic atom to hold information, it cannot flip. For the last ten years researchers have been asking: in order for the atom to stop flipping, how many atoms are needed to stabilize the magnet, and how long can it hold it information before it flips again? In the last two years, scientists in Lausanne and at IBM Almaden have figured out how to keep the atom from flipping, showing that a single atom can be a memory. To do this, researchers had to use very low temperatures, 40 Kelvin or -233 degrees Celsius. This technology is limited to extremely low temperature.”
thumbnail courtesy of phys.org