Ferroelectric random-access memory, or FRAM, relies on lining up dipoles (separated charges) to represent 0 and 1, giving it the speed of RAM and, notably, the ability to retain data without power. Unfortunately, FRAM does not offer as much storage space: dipoles in small ferroelectric bits do not all line up easily. Now University of Arkansas researchers may have discovered a way to shrink ferroelectric bits. They simulated the behavior of dipoles in nanosize disks and rods of perovskite, a promising ferroelectric material, and found that they spontaneously twist into left- and right-handed spiral shapes. Such vortices mark a new phase in ferroelectric materials, and because they are tiny and interact weakly with one another, they can be packed very closely together, which could increase their memory density 100,000 times. Read the group's report in the December 9, 2004, Nature.
This article was originally published with the title "Shrinking Memory" in Scientific American 292, 2, 33 (February 2005)